I'm aware this has already been asked, but with an update to Tor browser it seems a bit more difficult to manage. See here: How to run multiple Tor browsers with different IPs?
It requires editing TorButton preferences, which is no longer an easy thing to do. How do I change my settings to use custom proxy?
I see it's possible using linux: https://trac.torproject.org/projects/tor/wiki/doc/TorBrowser/Hacking
EDIT: I found this also: https://trac.torproject.org/projects/tor/ticket/14630
At the bottom, MikePerry says " ... you need to either edit the Torbutton about:config prefs 'extensions.torbutton.socks_host' and 'extensions.torbutton.socks_port', or set the environment variables TOR_SOCKS_HOST and TOR_SOCKS_PORT before starting TBB."
I tried doing that and it also did not work. I may have missed something very obvious though.