Thank you Pradeep,

I tried but for it is not working. User group has a related list with table Group Location Coverage [sys_group_covers_location] and then location field on this table is referenced to Location table. Please advise.

Thank you

Below is the script that I'm using !.

(function executeRule(current, previous /null when async/) {

// Add your code here

var userLoc = current.caller_id.location;

var gr = new GlideRecord('sys_user_group');

gr.addQuery('sys_group_covers_location.location', userLoc); //This field is a related list on the user groups

gr.addQuery('type', "mission_it");

gr.query();

if(gr.next());

{current.assignment_group = gr.sys_id;

}

})(current, previous);