The following instructions work on macOS 11.6 and other recent versions (see caveats at end):
In Finder, with the iPad (or iPhone) attached, select the device.
Click "Manage Backups"
In the selected backup directory, open "Manifest.db" in
sqlite3 or in a GUI SQLite browser you've installed from the App Store.
select distinct domain from Files; and find the domain for the app you want to get files from.
Get a list of all that app’s files with
select fileID, relativePath
where "domain" is "AppDomain";
(substitute the domain you identified)
The first column,
fileID, is the name of the backed up file in a subdirectory of the backup. Its parent directory is named by the first two characters of the fileID. The second column is the filename on the iPad or iPhone.
Edit the results into a script to get the files where you want them on your laptop. Or if you only want a few files, use the results to navigate in Finder.
- If you don't understand the above, you might not want to tamper with the mobile backup. I do understand it, and yet I still trashed mine and had to restore it from Time Machine.
- Something similar should work in other versions of macOS.