This is the “Eichenlaubmuster” camouflage, or “oak leaf” camouflage.
It is a German World War II camouflage pattern that was used from the early 1940s until 1945.
I couldn’t find a separate pattern, so I tried to recreate it by myself, including summer and autumn versions; I’m not sure how historically accurate my recreation is.
The pattern is seamless, I think, and measures 8000x8000.
How to Use
Just drag the material onto a layer with a mask, edit it however you like - and it's done!Use it as a fill, but I'd recommend using it differently on each part of the clothing—either way, do whatever you want.

Pattern