It looks like you have a second overlapping region in the arrange Window that is offset from the bar line slightly. The solution would be to delete that overlapping region, assuming it doesn't contain any needed content. If it does, merge them together so there is only one region.
I think you re asking two separate questions here:
1. Is there an un-merge feature? The answer is no, unless you use the Undo history.
2. Can you see overlapping regions in the Arrange Window? Yes, you can. Click on the region(s)in the area where they overlap and when you find the sweet spot (it's a bit of trial and error) one will come to the front and the other will move to the back. You can also usually see a dotted line where the overlap begins or ends as a visual cue that there is a hidden overlapping region underneath what you see.
Yeah, I try to avoid them too. But I used that command today. I brought a PT session of a trio recording into Logic. Brought each instrument in by track (guitar mic, guitar direct, etc), placed them on one track, used the Move Region to Original Record Position command and then used the New for Overlapped Regions command.
Everything worked great with a few caveats. Drag Mode was set to Overlap, had to set SMPTE offset to 00:00:00:00 to match the PT session, and the tracks created for the overlapping regions were "clones": I had to create unique tracks and move the regions.
Anyway, it all went very quickly all things considered. Now the editing......