LG smart TV xfinity stream app main menu question

I'm logged in and it's working beautifully, but once I pick a show to watch on live tv, how on earth do I get back to the main menu so I can pick something else to watch or get to my favorite channels or even my recorded shows. I've hit every button I can think of on the remote and i can't get back to the main menu without exiting xfinity and getting back in.