add_action('restrict_manage_posts',function(){global $typenow;if ('jet-booking'===$typenow && isset($_GET['page']) && $_GET['page']==='jet-abaf-calendar'){$taxonomy='purpose';// your taxonomy slug wp_dropdown_categories(array('show_option_all'=>'All Purposes','taxonomy'=>$taxonomy,'name'=>$taxonomy,'orderby'=>'name','selected'=>isset($_GET[$taxonomy]) ? $_GET[$taxonomy]:'','hierarchical'=>true,'depth'=>3,'show_count'=>false,'hide_empty'=>false,))}});add_filter('parse_query',function($query){global $pagenow;$taxonomy='purpose';if (is_admin() && $pagenow==='admin.php' && isset($_GET['page']) && $_GET['page']==='jet-abaf-calendar' && !empty($_GET[$taxonomy])){$term=intval($_GET[$taxonomy]);$query->query_vars[$taxonomy]=$term}});