I'm not completely sure what you are looking for. Terms are sometimes used differently, but usually a mastermind group is one where people who are close to peers meet and support each other. That's different than educational programs where at least one expert teaches and guides a group. Can you say further what you want? In general, the best advice is to start with your local real estate investment group and see what is available. In Chicago, I have to imagine there are multiple options, all with a different flavor and focus. Good luck!
I'm in some wholesale mastermind groups on facebook.