I built a customizable navigation drawer from scratch(didn't make use of the default drawer provided by Android Studio). In my weather app's navigation bar menu https://i.stack.imgur.com/SIjdx.jpg, whenever I select an option on the menu(say settings), it displays the contents of the option along with the bottom navigation view and my Activity's Toolbar contents which comprises of the nav hamburger icon, the edittext and the search button(the activity hosting my 3 fragments) which spoils the app and makes it look very ugly i.e. https://i.stack.imgur.com/gxj5n.jpg (From that screenshot, the entire content should be empty if implemented well). The case is the same for the other bar menu options. All I want is an empty space to work on, I want the app to only display the navigation bar contents without the rest. Example; https://i.stack.imgur.com/3Jtga.png Please how should I do this?

The view of the Navigation Menu is controlled by this code(on line 185):

@Override
    public boolean onNavigationItemSelected(@NonNull MenuItem item) {
        switch (item.getItemId()) {
            case R.id.settings_id:
                getSupportFragmentManager().beginTransaction().replace(R.id.fragment,
                        new Settings()).commit();
                break;
            case R.id.ads_upgrade_id:
                getSupportFragmentManager().beginTransaction().replace(R.id.fragment,
                        new Upgrade()).commit();
                break;
            case R.id.privacy_policy_id:
                getSupportFragmentManager().beginTransaction().replace(R.id.fragment,
                        new Privacy_Policy()).commit();
                break;
        }
        drawer.closeDrawer(GravityCompat.START);

        return true;
    }

"fragment" there represents that I'm currently using my fragment's container view on my activity to display the Nav menu contents which I know is wrong for sure, so what should I use in replace? I lack strong experience as it's my first time building an app and I've tirelessly spent 3 hours on my own trying to figure out the issue which proved abortive.

Here is my Activity code:

public class HomeActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
    private DrawerLayout drawer;
    // Last update time, click sound, search button, search panel.
    TextView timeField;
    MediaPlayer player;
    ImageView Search;
    EditText textfield;
    // For scheduling background image change(using constraint layout, start counting from dubai, down to statue of liberty.
    ConstraintLayout constraintLayout;
    public static int count = 0;
    int[] drawable = new int[]{R.drawable.dubai, R.drawable.norway, R.drawable.eiffel_tower, R.drawable.hong_kong, R.drawable.statue_of_liberty,
            R.drawable.beijing, R.drawable.chicago, R.drawable.colombia, R.drawable.vienna,R.drawable.tokyo};
    Timer _t;

    private WeatherDataViewModel viewModel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_home);
        // use home activity layout.

        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        // Allow activity to make use of the toolbar

        drawer = findViewById(R.id.drawer_layout);
        NavigationView navigationView = findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);

        viewModel = new ViewModelProvider(this).get(WeatherDataViewModel.class);

        // Trigger action to open & close navigation drawer
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(this, drawer, toolbar
                , R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.addDrawerListener(toggle);
        toggle.syncState();

        timeField = findViewById(R.id.textView9);
        Search = findViewById(R.id.imageView4);
        textfield = findViewById(R.id.textfield);
        //  find the id's of specific variables.

        BottomNavigationView bottomNavigationView = findViewById(R.id.bottomNavigationView);
        // host 3 fragments along with bottom navigation.
        final NavHostFragment navHostFragment = (NavHostFragment) getSupportFragmentManager().findFragmentById(R.id.fragment);
        assert navHostFragment != null;
        final NavController navController = navHostFragment.getNavController();
        NavigationUI.setupWithNavController(bottomNavigationView, navController);

        // Make hourly & daily tab unusable
        bottomNavigationView.setOnNavigationItemSelectedListener(item -> {

            if (getSupportFragmentManager().getBackStackEntryCount() > 0) {
                getSupportFragmentManager().popBackStack();
            }
            return false;
        });

        navController.addOnDestinationChangedListener((controller, destination, arguments) -> navController.popBackStack(destination.getId(), false));

        // For scheduling background image change
        constraintLayout = findViewById(R.id.layout);
        constraintLayout.setBackgroundResource(R.drawable.dubai);
        _t = new Timer();
        _t.scheduleAtFixedRate(new TimerTask() {
            @Override
            public void run() {
                // run on ui thread
                runOnUiThread(() -> {
                    if (count < drawable.length) {

                        constraintLayout.setBackgroundResource(drawable[count]);
                        count = (count + 1) % drawable.length;
                    }
                });
            }
        }, 5000, 5000);

        Search.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                // make click sound when search button is clicked.
                player = MediaPlayer.create(HomeActivity.this, R.raw.click);
                player.start();

                getWeatherData(textfield.getText().toString().trim());
                // make use of some fragment's data

                Fragment currentFragment = navHostFragment.getChildFragmentManager().getFragments().get(0);
                if (currentFragment instanceof FirstFragment) {
                    FirstFragment firstFragment = (FirstFragment) currentFragment;
                    firstFragment.getWeatherData(textfield.getText().toString().trim());
                } else if (currentFragment instanceof SecondFragment) {
                    SecondFragment secondFragment = (SecondFragment) currentFragment;
                    secondFragment.getWeatherData(textfield.getText().toString().trim());
                } else if (currentFragment instanceof ThirdFragment) {
                    ThirdFragment thirdFragment = (ThirdFragment) currentFragment;
                    thirdFragment.getWeatherData(textfield.getText().toString().trim());
                }
            }

            private void getWeatherData(String name) {

                ApiInterface apiInterface = ApiClient.getClient().create(ApiInterface.class);

                Call<Example> call = apiInterface.getWeatherData(name);

                call.enqueue(new Callback<Example>() {
                    @Override
                    public void onResponse(@NonNull Call<Example> call, @NonNull Response<Example> response) {

                        try {
                            assert response.body() != null;
                            timeField.setVisibility(View.VISIBLE);
                            timeField.setText("First Updated:" + " " + response.body().getDt());
                        } catch (Exception e) {
                            timeField.setVisibility(View.GONE);
                            timeField.setText("First Updated: Unknown");
                            Log.e("TAG", "No City found");
                            Toast.makeText(HomeActivity.this, "No City found", Toast.LENGTH_SHORT).show();
                        }
                    }

                    @Override
                    public void onFailure(@NotNull Call<Example> call, @NotNull Throwable t) {
                        t.printStackTrace();
                    }

                });
            }

        });
    }

    @Override
    public boolean onNavigationItemSelected(@NonNull MenuItem item) {
        switch (item.getItemId()) {
            case R.id.settings_id:
                getSupportFragmentManager().beginTransaction().replace(R.id.fragment,
                        new Settings()).commit();
                break;
            case R.id.ads_upgrade_id:
                getSupportFragmentManager().beginTransaction().replace(R.id.fragment,
                        new Upgrade()).commit();
                break;
            case R.id.privacy_policy_id:
                getSupportFragmentManager().beginTransaction().replace(R.id.fragment,
                        new Privacy_Policy()).commit();
                break;
        }
        drawer.closeDrawer(GravityCompat.START);

        return true;
    }

    @Override
    public void onBackPressed() {
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
            // Open/close drawer animation
        }
    }
}

In case you require any other code to look into the issue, please let me know. I'm just trying to avoid posting too much

EDIT:

My old bottomtabs nav graph:

<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/my_nav"
    app:startDestination="@id/firstFragment">

    <fragment
        android:id="@+id/firstFragment"
        android:name="com.viz.lightweatherforecast.FirstFragment"
        android:label="fragment_first"
        tools:layout="@layout/fragment_first" />
    <fragment
        android:id="@+id/secondFragment"
        android:name="com.viz.lightpreciseweatherforecast.SecondFragment"
        android:label="fragment_second"
        tools:layout="@layout/fragment_second" />
    <fragment
        android:id="@+id/thirdFragment"
        android:name="com.viz.lightpreciseweatherforecast.ThirdFragment"
        android:label="fragment_third"
        tools:layout="@layout/fragment_third" />
</navigation>

My new nav bar graph:

<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/bar_nav"
    app:startDestination="@id/firstFragment">

    <fragment
        android:id="@+id/firstFragment"
        android:name="com.viz.lightweatherforecast.FirstFragment"
        android:label="fragment_first"
        tools:layout="@layout/fragment_first" />
    <fragment
        android:id="@+id/settings_id"
        android:name="com.viz.lightweatherforecast.Settings"
        android:label="@string/settings"
        tools:layout="@layout/settings" />
    <fragment
        android:id="@+id/ads_upgrade_id"
        android:name="com.viz.lightweatherforecast.Upgrade"
        android:label="@string/upgrade_to_remove_ads"
        tools:layout="@layout/upgrade" />
    <fragment
        android:id="@+id/privacy_policy_id"
        android:name="com.viz.lightweatherforecast.Privacy_Policy"
        android:label="@string/privacy_policy"
        tools:layout="@layout/privacy_policy"/>

</navigation>