Switching Bluetooth audio

Bought my 2013 4Matic back in January and am loving it so far. Figured I would tap into the knowledge base here for a question.
I frequently listen to music over Bluetooth using my mobile phone. Once you are playing music and switch to navigation, how do you return to the Bluetooth interface for music. A.k.a., if I look on my console, the closest option I have is radio and pressing that automatically to the Sirius interface and the satellite starts playing. Any thoughts? Let me know if I am not explaining clearly
I want to be able to navigate away from the Bluetooth interface and then return to it with no hiccups


