orderby with city and distance

I want to sort with distance and city or only with city.
I don′t know how to use this code in my functions.php

apply_filters( 'gmw_pt_location_query_clauses', $clauses, $this->form );

and which parameter I must change ?
I have tried this code in my functions.php

function gmw_pt_custom_orderby_query( $query_args, $form ) {
   // verify that we are in page load results query.
	if ( empty( $form['page_load_action'] ) ) {
		return $query_args;
	}
 
	$query_args['orderby'] = city';
	$query_args['order']   = 'ASC';
 
	return $query_args;
}
add_filter( 'gmw_pt_search_query_args', 'gmw_pt_custom_orderby_query', 99, 2 );