i select ul.menu within li's (submenu's) don't have "active-trail" class
html:
<ul class="menu"> <li>item 1</li> <li class="expanded">item 2 <ul class="menu"> <li>sub item a</li> <li>sub item b</li> <li>sub item c</li> </ul> </li> <li class="expanded">item 3 <ul class="menu"> <li>sub item d</li> <li>sub item e</li> <li>sub item f</li> </ul> </li> <li class="expanded active-trail">item 4 <ul class="menu"> <li>sub item g</li> <li>sub item h</li> <li>sub item i</li> </ul> </li> </ul>
jquery:
$('#region-menu ul.menu > li.expanded:not:has(active-trail) ul.menu ').addclass('hidden')
this do:
$('li.expanded:not(.active-trail) ul.menu').addclass('hidden');
you close, selector need inside :not()
class .active-trail