In your situation, how about the following sample script?

Sample script:

function myFunction() {
  const srcSheetName = "source"; // Please set the source sheet name.
  const dstSheetName = "des"; // Please set the destination sheet name.

  // Retrieve source and destination sheets.
  const ss = SpreadsheetApp.getActiveSpreadsheet();
  const [srcSheet, dstSheet] = [srcSheetName, dstSheetName].map(s => ss.getSheetByName(s));

  // Retrieve source values and create an object for putting to the destination sheet.
  const srcValues1 = srcSheet.getRange("A1:C" + srcSheet.getLastRow()).getValues();
  const obj1 = srcValues1[0].map((_, c) => srcValues1.map(r => r[c])).reduce((o, [h, ...v]) => (o[h] = v, o), {});
  const srcValues2 = srcSheet.getRange("F2:G" + srcSheet.getLastRow()).getValues();
  srcValues2.forEach(([f, g]) => {
    if (g > 1) {
      for (let i = 0; i < g - 1; i++) {
        obj1[f] = [...obj1[f], ...obj1[f]];
      }
    }
  });
  const obj2 = Object.values(obj1).flat().reduce((o, a) => (o[a] = o[a] ? o[a] + 1 : 1, o), {});

  // Retrieve the values of column "A" from the destination sheet and create an array for putting to Spreadsheet.
  const dstRange = dstSheet.getRange("A2:A" + dstSheet.getLastRow());
  const dstValues = dstRange.getDisplayValues().map(([a]) => [obj2[a] || 0]);

  // Put the result values to the column "B" of the destination sheet.
  dstRange.offset(0, 1).setValues(dstValues);
}

• From your provided Spreadsheet, the sample sheet names are source and des. Please modify this for your actual situation.
• When you run this script, the values are retrieved from the source sheet, and the groups are increased using the values from column "G", and the count of each value (1, 2, 3) is calculated. And, the result values are put in column "B" of the destination sheet.

Note:

• This sample script is for your provided Spreadsheet. When you change the structure of the Spreadsheet, this script might not be able to be used. Please be careful about this.

References:

• reduce()
• map()