restore from a point of path, not the latest ?(big sur)

I'm very confused now.

my new macBook Air M1 chip.

Trying to back to a half day ago, I'm struggling to "recovery" mode.

Restore mode refuses to restore, but force to re-install.

So I all erased, and now newly installing, but again, the latest backup only.

I find what "migration assistant" is (for me, it's very old tool. I really realized it came back).

But looking at Apple's

Restore your Mac from a backup - Apple Support

https://support.apple.com/en-us/HT203981

there is no selection from when to restore.

How can I do?