<div id='d1'>
   <ul id='ul1'>
      <li id='l11'>l1-1</li>
      <li id='l12'>l1-2
         <ul id='ul2'>
            <li id='l21'>l2-1</li>
            <li id='l22'>l2-2
               <ul id='ul3'>
                  <li id='l31'>l3-1</li>
                  <li id='l32'>l3-2</li>
                  <li id='l33'>l3-3</li>
               </ul>
            </li>
            <li id='l23'>l2-3</li>
         </ul>
      </li>
      <li id='l13'>l1-3</li>
   </ul>
</div>

<script type="text/javascript">
   console.log($('l12').up());
   $$('#ul2 > li').each(function(el) {
      console.log(el);
   });
</script>