Question force z-index on UI element without hierarchy changes?

Is there any way to FORCE the z-index on a UI element without messing with the hierarchy?

I have a small tree of elements like this:

• A
  
  • a1
  • a2
• B
  • b1
  • b2
• C
  • c1
  • c2

I I need to make sure that elements a2, b2 and c2 are always on top of everything else (tooltips). Because this whole thing is dynamically placed (player cursor position), I need to keep the hierarchy intact.

 

It should be possible to override the default hierachy based order for some elements by creating a nested canvas and setting either sorting layer or order in layer for that nested canvas.

 

You mean having a canvas as a parent of a2, bc2, c2, like:

• A
  • a1
  • canvas
    • a2

?