Grouped countries

HTML

<script src="http://www.ammap.com/lib/3/ammap.js"></script>
<script src="http://www.ammap.com/lib/3/maps/js/worldLow.js"></script>
<div id="mapdiv" style="width: 100%; height: 370px;"></div>

JavaScript

var map;
AmCharts.ready(function() {
    map = new AmCharts.AmMap();
    map.pathToImages = "http://www.ammap.com/lib/images/";
    //map.panEventsEnabled = true; // this line enables pinch-zooming and dragging on touch devices
    var dataProvider = {
        mapVar: AmCharts.maps.worldLow,
        zoomLevel: 3.5,
        zoomLongitude: 10,
        zoomLatitude: 52
    };
    map.areasSettings = {
        unlistedAreasColor: "#DDDDDD",
        rollOverOutlineColor: "#FFFFFF",
        rollOverColor: "#CC0000",
        balloonText: "[[title]] : [[customData]]"
    };
    dataProvider.areas = [
    {
title: "Albania",
id: "AL",
color: "#FFCC33",
customData: "2016",
groupId: "Ruben"},
    {
title: "Australia",
id: "AU",
color: "#F5A9F2",
customData: "2016",
groupId: "Sami"},
    {
title: "Austria",
id: "AT",
color: "#FFCC33",
customData: "2016",
groupId: "Ruben"},
    {
title: "Azerbaidjan",
id: "AZ",
color: "#3366CC",
customData: "2016",
groupId: "Antoine"},
    {
title: "Belgium",
id: "BE",
color: "#66CC99",
customData: "15/05/2015",
groupId: "Robby"},
    {
title: "Brazil",
id: "BR",
color: "#3366CC",
customData: "2016",
groupId: "Antoine"},
    {
title: "Bulgaria",
id: "BG",
color: "#FFCC33",
customData: "22/07/2015",
groupId: "Ruben"},
    {
title: "Bosnia",
id: "BA",
color: "#FFCC33",
customData: "2016",
groupId: "Ruben"},
    {
title: "Botswana",
id: "BW",
color: "#3366CC",
customData: "2015",
groupId: "Antoine"},
    {
title: "Belarus",
id: "BY",
color: "#FFCC33",
customData: "2015",
groupId: "Ruben"},
    {
title: "Congo",
id: "CD",
color: "#FFCC33",
customData: "2008",
groupId: "Ruben"},
    {
title: "Croatia",
id: "HR",
color: "#FFCC33",
customData: "02/08/2013",
groupId: "Ruben"},
    {
title: "Czech Republic",
id: "CZ",
color: "#66CC99",
customData: "20/04/2015",
groupId: "Robby"},
    {
title: "Ethiopia",
id: "ET",
color: "#FFCC33",
customData: "2005",
groupId: "Ruben"},
    {
title: "Canada",
id: "CA",
color: "#66CC99",
customData:...