Use overlap at offset. Only you set it in pixels
In my example you have to set for both sides, so you cave to make 2 sets of conditions.
one might be overlap 20,0 (20 is X and 0 is Y)
The other would be -25,0
This way the overlap works from both sides.
I use this in a platformer of mine:
Player > is Overlapping Enemy 25,0 > do something
Player > is Overlapping Enemy -25,0 > do something
In your case it sounds like you'll need change overlap for Y and in only one direction. Hope this helps.