gistfile1.txt

add_filter( 'propertyhive_property_query_meta_query', 'filter_search_by_address_three', 10, 2 );
function filter_search_by_address_three( $meta_query, $query )
{
    if ( isset( $_REQUEST['address_three'] ) )
    {
        $meta_query[] = array(
            'key'     => '_address_three',
            'value'   => sanitize_text_field($_REQUEST['address_three']),
        );
    }
    
    return $meta_query;
}