I've been tinkering with Tor for a while, and can't figure out a way to do this. I would like for each window to have its own identity, to allow me to be logged into multiple accounts on a website. Unfortunately, Tor has nothing that allows you to be able to have independent identities per window, or a way to prevent a website from sharing your log in status to the next window. To my knowledge, anyways. Keep in mind, I want to be able to log into multiple accounts, simultaneously, on the same website. So no "just log out or get a new identity" please, lol. I hope someone has the solution to my issue.
The current Tor Browser doesn't really support this. The best workaround would probably be to somehow start multiple instances of Tor and connect through them. You could run multiple Tor instances with their own data directories, specifying different ports and then open up multiple browsers to proxy through the individual ports.