User Link Field, only show System Users (and not show Website users)?

Is it possible to show both System Users and Website Users on Link Field?

I got the solution, using client script for filtering,

frappe.ui.form.on("Innovation Request", "onload", function(frm){
    frm.set_query("user", function(){
        return {
            filters: {
                "ignore_user_type": 1
            }
        }
    });
});

Looking into the code, looks like ignore_user_type is a special param.