I am new to javascript. Let's say I have a block

<div class="nav">
  <div id="rectangle" class="rectangle">
    Content...
  </div>
</div>

And I am using this block in some script

document.getElementById('navShareLink');

But now I want to add another one to the nav block, let's say

<div class="nav">
  <div id="rectangle" class="rectangle">
    Content...
  </div>

  <div id="to-top" class="to-top">
    Content...
  </div>
</div>

The question is, can I use two blocks at once in this line, like

document.getElementById('rectangle', 'to-top');

If not, what are the options?