Dropping something over undesired (under-overlapped) div

Dropping something over undesired (under-overlapped) div


Droppable has the greedy property that works well with nested DIV.
But lets assume the case in which the DIV are not parent-son but
brothers, something like:
<div>
<div>DIV 1</div>
<div>DIV 2</div>
</div>
With simple css code, using "position: absolute", we can overlap both
DIV. Dragging an element over the overlapped zone, we will discover
that
BOTH div get the drop event. Technically, the user would like only
the DIV that is on the top to get the drop event.
Is there any way to achieve this?
thanks a lot!
David