OnMouseUpAsButton clicks through

Unity Engine
1

I am trying to implement buttons using OnMouseUpAsButton on a Sprite with box collider. The problem is when I have 2 sprite button overlapping each other, when clicking on the overlapping area, both buttons are activated. How could I prevent the button on the lower layer from activating and the the top layer eat the event?

Thanks.

2

Anyone have any idea?

I guess I could write my own touch handling manager to sort the layers and only pass touch to the top layer, but I would think that this should be basic enough for Unity to handle natively without need for such a work around and I am just not aware of it.