Branches instead of multiple forks, or how do I solve my need of two forks

I have a fork of a repo (called AndroidAPS) where I do some development but mainly deploying for my private purpose. Now I want to have a copy of another persons fork from the same base repository. I have understood I can not make two forks from the same repo. I guess I have to do it somehow with branches, but how can I do this? Are there any way of doing it to keep traceability?

Hope someone can help me out, ask if soemthing sound stupid or unclear.

In principle: Add that other person’s fork to your local repository as a remote (see Git Basics: Working with Remotes). After fetching you can create local branches and push to your own Github repository as you like. Note that your branch names don’t have to match the source repository.

Depends on what you want to trace. Git will automatically keep track of the history, of course, but it doesn’t track where specific commits were fetched from. A thing I’ve done to track the meaning of branches in my repository is to make notes in the repository wiki.