In the settings you can specify when the doors unlock again. Go to "Doors and windows" and choose "Lock/unlock". By selecting "Unlock doors at end of trip" they will unlock after switching off the vehicle with the Start/Stop button.
Easily pick up passengers by pressing the center lock button while driving below 10 mph. And of course, you can always open the doors manually from the inside by pulling the door handle.
Link to watch BMW USA Genius How-to Video: How to Automatic Door Lock with the BMW Operating System 8 | BMW USA
