Hi Bill. There isn’t currently an action available for this. I think the intention is that to close the topmost panel, the user would click outside of the panel that should be closed.  When you’ve got overlapping sliding panels, the scenario gets a bit more complicated. If you would like, you can of course share this as an idea with specifics about what’s involved in your use-case. 

A specific use case would be building a mobile application that has multiple layers. Just like the mobile page builder had page panels, this would simulate that experience allowing a user to go down multiple layers and then back as they please vs. back to home. 

I don’t know if this is still an issue/concern but at some point there must have been an update to this action that might help! Now the action to close sliding panels gives the option to select ‘Close all’ or ‘Close topmost’ for the sliding panels and popups as well.