(legacy) menu item collapse, https://github.com/opnsense/core/issues/401

src/www/head.inc

@@ -145,6 +145,15 @@ $pagetitle = gentitle( $pgtitle );
 				event.preventDefault();
 			});
 
+			// hide submenu items
+			$('#mainmenu .list-group-item').click(function(){
+					$('#mainmenu .list-group-item').each(function(){
+							if ($(this).attr('aria-expanded') == 'true') {
+								$("#"+$(this).attr('href').substring(1,999)).collapse('hide');
+							}
+					});
+			});
+
 		});
 		//]]>
 		</script>