Google Apps Script Gmail: when sublabel and parent label, only sublabel

script.js

function startFunction() {
  // If email has 1-Ingrid label and sublabel label then delete 1-Ingrid:
  mainFunction("Ingrid");
  mainFunction("Claire");
}

function mainFunction(name) {
  var amountOfLabelsRemoved = 0;
  var subLabelsWithUsername = getSubLabels(name);
  for (var x = 0; x < subLabelsWithUsername.length; x++) {
    var gmailApiUserLabel = GmailApp.getUserLabelByName("1-" + name);
  while (gmailSearch(name,subLabelsWithUsername).length > 0) {
    var results = gmailSearch(name,subLabelsWithUsername);
    gmailApiUserLabel.removeFromThreads(results);
    amountOfLabelsRemoved = amountOfLabelsRemoved + results.length;
  }
  }
  Logger.log("Amount of Labels Removed for user " + name + ": " + amountOfLabelsRemoved);
}

function trialAndErrorTest() {
  Logger.clear();
  var subLabelsWithUsername = getSubLabels("ingrid");
gmailSearch("ingrid",subLabelsWithUsername);
}

function getSubLabels(name) {
  //This function creates array with all sublabels of 1-NAME
  var results = [];
  var subLabelsWithUsername = [];
  //Retrieve all labels and convert to text array(results)
  var labels = GmailApp.getUserLabels();
  for (var i = 0; i < labels.length; i++) {
    results.push(labels[i].getName());
  }
  //Filter all labels for sublabels
  for (var i = 0; i < results.length; i++) {
    if(results[i].indexOf('/')>0){
      var isASubLabel = results[i];
      //Filter those labels for the labels of 1-NAME parent
      if(isASubLabel.indexOf("1-" + name)>=0){
        subLabelsWithUsername.push(isASubLabel)};
    }
  }
  return subLabelsWithUsername;
  Logger.log("function getSubLabels finished executing");
}

function gmailSearch(name,subLabelsWithUsername) {
  //make search query (filter)
    //var nieuwsbriefLabel = "1-" + name + "-Nieuwsbrieven";
  for (var label in subLabelsWithUsername) {
    if (filter == null) {
  var filter = "(label:1-" + name + " AND label:" + subLabelsWithUsername[label] + ") ";
    } else {
      filter += "OR (label:1-" + name + " AND label:" + subLabelsWithUsername[label] + ") ";
    }
  }
  //concatenate filter
    // +" AND label:" + nieuwsbriefLabel;
    var results = GmailApp.search(filter, 0, 40);
  return results;
  Logger.log("function gmailSearch finished executing");
}