I would like to be able to select all elements of class zz that are descendants of an element of class xx but not a descendant of class yy.
Consider the following:
<div class="xx">
... arbitrary depth ...
<div class="zz" id="1">
</div>
<div class="yy">
<div class=zz" id="2">
</div>
...
</div>
...
</div>
The selector I'm looking for would in the above case return the id1 element but not id2 element.