Note: I'm using Guix with other distribution, not GuixSD.

I was trying to find out what is the "working tree" in my case, and I
decided to investigate "/gnu/store", and I found three possible places
that are directories:

/gnu/store/...-guix-0.11.0-1.4420
/gnu/store/...-guix-latest
/gnu/store/...-guix-source

Which one is my "working tree"?