Based on Role Profile, users are not listing

I have a field called Approver. Its linked to User. But its listing all the users. But i need to list the users who have particular role profile name. i have done the below code. But its not working. Please help me regarding this.

frm.set_query(“approver”, function() {
return {
filters: [
[‘User’, ‘role_profile_name’, ‘=’, ‘Employee’]

Can anyone please help me regarding this