Need some help about overlapping multiple user widgets

I have both** Inventory** widget and** Equipment** widget on the same container panel so that I can change the widget index to design which one is overlapping the other in visible time.

Many buttons and other widgets will fill in the** Inventory** or Equipment in the future, they all need mouse events.

What I think is that I can cover a mask which captures O****nMouseButtonDown, and then I post a message to the parent widget to reorder Inventory and Equipment, but at the same time, this OnMouseButtonDown event also hava to be captured by widgets under the mask.

But I find out that there are only two options for OnMouseButtonDown: Handled and Unhandled. Handled will kill the event, Unhandled will pass the event to next layer of UMG, but not the brother widgets I hope.

The relationship about Inventory and Equipment is like the pics below, what I want is that I click any part of Inventory, Inventory will display in front of the Equipment.

Thanks in advance.