How to restore a specific file from APFS Time Machine backup drive with tmutil?

Question

I've been using an HFS+ drive for Time Machine, but I recently formatted a drive in APFS as my Time Machine backup drive on macOS Monterey. Now I find the implementation with APFS very confusing. If I list things on the root directory of the drive with ls, the results are as follows:

.fseventsd
.Spotlight-V100
2022-12-03-020353.previous
backup_manifest.plist

And upon further inspection, 2022-12-03-020353.previous only contains the latest version of files, older backups are not visible. On an HFS+ TM backup drive, there should be a Backups.backupdb that contains all the backups with timestamps, which to my understanding is no longer the case for APFS since Big Sur. Now if I do tmutil listbackups, I still get a list of backup timestamps instantly, which looks like the following, though I don't know what to do with them:

……
2022-12-02-151624.backup
2022-12-02-171818.backup
2022-12-03-000232.backup
2022-12-03-020353.backup

From what I found online, the older backups are stored as APFS snapshots, the question is though, how do I restore specific files from them? I mean, without the Time Machine GUI, but in the command line with tmutil? On HFS+ drives I can simply do tmutil restore /Volumes/TM/Backups.backupdb/<timestamp>/Macintosh HD/<src> <dst>, how do I do the same thing with an APFS drive? Do I need to mount a specific snapshot first before restoring? How to do that in the command line with timestamps gathered by tmutil listbackups? Because waiting for snapshots for the backup hard drive to appear in Disk Utility.app takes forever.

Apologies if this has been asked before, but search engines haven't been kind to me, all I could find about APFS TM backups were about local snapshots and deleting a backup by timestamp.

Answer 1

I figured it out myself, here's the answer, in the form of a Bash script, use at your own discretion. Basically you have to mount a backup snapshot with mount_apfs by its name, which can be obtained through diskutil info, then you can access the files normally with whatever tool you like.

Also, I learned that the Time Machine GUI essentially does the same thing, it just mounts all of the snapshots under /Volumes/.timemachine/<backup volume UUID>, but you have to enter the TM GUI once after each re-mount, otherwise it only mounts the oldest snapshot, but the TM GUI isn't controllable from a script (maybe possible with AppleScript? idk). Also, it does mounts all the snapshots when OS restarts.