After the format I put this 500GB drive back into the ReadyNAS and (THOUGHT

There are about 15,000 pictures in about 1,000 different folders. Below, the first picture shows the folder structure --inside the red circle--of the "BTRFS" that I would like to recover but NEED HELP to ensure I do not lose all the photos of my family and more.

Second pic shows the hex data if that helps anyone.
Third pic is the scan from TestDisk I hope to rescue my pics and docs.
Any advice offered (Linux dumb here, but have an Ubuntu VM on hand) would be great (please speak slowly, and clearly) help and appreciated!
SGT Oldy