I have a lot of instances with overlapped elements / graphics where hide visibility and pop up graphics are used throughout program depending on state / button presses
Right click and use the send to back / bring to front I find easiest to work when using layers of elements
Also can copy top element delete, work on bottom element and paste deleted one back when your done
I find sometimes Copy / Paste and a couple blank HMI Editing pages is useful in keeping all elements in proper location for building and troubleshooting
deleting top layered elements Copy / Paste some more and mesh it back up together
Sometimes using coordinates to mark exact location of elements if you want to move something out of the way and place it back later
All of this is easy when its your project and you're the builder, but I do see this being a bit of a pain for the next person dealing with hidden elements in some one else's program
(but that's what "find tag" is used for)