Currently, Switcher Studio does not offer simultaneous streaming across different platforms from directly within the app. If you would like to stream across platforms, there are a few third-party services that work well with Switcher Studio. We recommend Castr and Switchboard.
This blog post walks through the process of using one of those services with Switcher Studio: Livestream to Multiple Platforms at Once with Simulcasting
While Switcher Studio doesn't provide simulcasting across different platforms, we do have an option to broadcast to multiple destinations on Facebook simultaneously. Check out this article for more information about Crossposting on Facebook.