Lower media volume when connected to bluetooth

I have a task that when I'm in the neighborhood of my office the Ringtone changes to a discrete ringtone and lower the volume to 1, my notification volume is changed to 1 and I would like to change the media volume (when I am not connected to bluetooth) to 0. So I set also "media volume: 0". But this changes the "mediavolume bluetooth" because I am still connected to my carkit. When I leave the car, bluetooth connection is terminated, but the media volume (not connected) is still 15 as it was before I entered the car.

How is it possible to change notconnected media volume when I am connected, and how can I change "bluetooth media volume" when I am not connected?