[adeuel]

For the past few BMWs, I have saved my "Presets" selection as a speed dial button on one of the numeric pad buttons above the AC unit.

It does take you out of carplay and to the iDrive preset menu, but you can immediately hit the "Back" button below iDrive and it goes back to carplay, (waze). From there, I use the wheel on the right side of steering wheel to scroll through the radio/XM presets in the tach display, leaving carplay on the main screen.

To set the presets button on the key pad, navigate to the presets screen and then press and hold whatever button you want to store it in.