Can't find the backup files directly on the uSD card

I can't seem to find the backup files on a uSD card when searching, using a Mac and Finder

This is the uSD card carrying my previous iteration of Octopi.
I was running an older version which gave me an initial error message and there were instructions on the best way to update using the Octoprint Disk Imager. I made a new instance onto a new uSD card and that's now installed and working.
Before doing that, I made a backup using the Octopi GUI, then removed the uSD card, which is the one where I'm now searching for the backup file/s.
I can see all of the other expected files, so the viewing system is working.

The files will be stored under /home/pi/. octoprint/data/backup I believe, and .octoprint is usually a hidden folder so you may have to enable viewing hidden things.