Since I've never heard of this, I decided to try it. I haven't tried an inset shadow yet, but it certainly could be used for that.
I had a set of 3 screenshots in an open Inkscape doc, where I had made several circles, to indicate certain areas. I dragged all the screenshots together, so that they partially overlapped, and dragged their circles too, since from the description, it sounded like objects in more than 1 z-order "layer" was needed. I'll attach it, in case anyone might want to see it....oh, well I'm not sure if we can attach things in this board, but I'll make a link.
So anyway, it made a clipping path out of everything in the group, except for the imported raster images, of course. The circles were clipped by a clone of the circle, and the text was clipped by a clone of the text! And the raster images were clipped by them as well! It's hard to see, but both the circles and the rasters were clipped by the text clone!
Warning, is approx 3.5 mb, due to the 3 embedded rasters. Might be a little slow to open.
https://inkscapecommunity.com/jd/clipgroup.svg Select the group, and do Create Clip Group.
Is it just me, or should everything in the context menu also exist in the window somewhere? It seems odd to me that the only way to access something, is by the context menu.