Get unique parent categories (service catalog categories) - GlideAggregate - and grab their subcategories

var ga= new GlideAggregate('sc_category'); ga.addAggregate('COUNT', 'parent'); ga.addQuery('sc_catalog','9f6ef0cddb028f80edfc7cbdae96191c'); ga.addNotNullQuery('parent'); ga.addHaving('COUNT', '>', 0); ga.query(); var dupls=[]; var parentCats=[]; dupls.push("The following " + ga.getRowCount() + " records are duplicate on parent"); while (ga.next()) { var DuplLine=ga.getAggregate('COUNT', 'parent') + " => " + ga.getElement('parent.title'); dupls.push(DuplLine); //gs.print(DuplLine); parentCats.push(ga.getElement('parent.title') ); } var output=parentCats.toString(); output=output.replaceAll(",","\n"); gs.print(output);

output: 

*** Script: Hardware
Software
Devices
Accessories
Storage
Servers
Technical
Telephony

for the subcategories:

parentCats.forEach(myFunction);

function myFunction(item, index) {
 //gs.print( index + ":" + item.title);
 //gs.print( index + ":" + item.sys_id);

   gs.print('NEXT CATEGORY BATCH: ************' + item.title); 
   var grCats= new GlideRecord('sc_category');
   grCats.addQuery('parent', item.sys_id);
   grCats.query();
   
   while (grCats.next()){
       gs.print(grCats.title);
 
   }
}