RCCWP_Menu::FilterPostsPagesList PHP Method

    public static function FilterPostsPagesList($where)
    {
        global $wpdb;
        if (isset($_GET['filter-posts'])) {
            $panel_id = $_GET['custom-write-panel-id'];
            $where .= " and {$wpdb->postmeta}.meta_key = '_mf_write_panel_id' and {$wpdb->postmeta}.meta_value = '{$panel_id}' ";
        }
        return $where;
    }