function onOpen() {
  var spreadsheet = SpreadsheetApp.getActiveSpreadsheet();
  var menuItems = [
    {name: 'Gearset stats dropdown', functionName: 'onEdit'}
  ];
  spreadsheet.addMenu('Custom Functions', menuItems);
}

function onEdit(e) {
  if(e != undefined) {
    if(e.range.getColumn() == 3) {
      var ss = SpreadsheetApp.getActiveSpreadsheet();
      var Tr = ss.getRange("'Body Armor'!C2:C50").getValues(); //Testrange
      // Variables and sheetnames
      var b = "'Body Armor'!";
      var g = "GS256!" ;
      var gC = "'GS256 Classified'!";
      var h = "B10:B27";
      var l = "B28:B36";
      // Get DV ranges
      var gh = ss.getRange(g+h) ;
      var ghc = ss.getRange(gC+h);
      var gl = ss.getRange(g+l);
      var glc = ss.getRange(gC+l);
      // Build DV rules
      var ghr = SpreadsheetApp.newDataValidation().requireValueInRange(gh,true);
      var ghcr = SpreadsheetApp.newDataValidation().requireValueInRange(ghc,true);
      var glr = SpreadsheetApp.newDataValidation().requireValueInRange(gl,true);
      var glcr= SpreadsheetApp.newDataValidation().requireValueInRange(glc,true);
      // Loop through each cell
      for(i=0;i<Tr.length;i++) {
        var j = i+1;
        var Hr = ss.getRange(b+"H"+j);
        var Jr = ss.getRange(b+"J"+j);
        var Lr =  ss.getRange(b+"L"+j);
        // Test the test range and apply corresponding DV
        if (Tr[i][0] == true) {
          Hr.setDataValidation(ghcr);
          Jr.setDataValidation(ghcr);
          Lr.setDataValidation(glcr);
        }
        else {
          Hr.setDataValidation(ghr);
          Jr.setDataValidation(ghr);
          Lr.setDataValidation(glr);
        }
      }
    }
  }
}