The concept
The parking brake is primarily intended to prevent the vehicle from rolling while parked; it brakes the rear wheels.

See also:
Enabling operation in the rear
Only possible via the iDrive in the front.
1. "Settings"
2. "Allow rear control"
3. Select the desired priority.
...
Increasing desired speed
Repeatedly press the lever to the resistance
point or beyond, arrow 1, until the desired speed
is reached.
▷ Each time the lever is pressed to the point of
resistance, the desired speed i ...
Note
Children in the vehicle
Do not leave children unattended in the
vehicle; otherwise, they could endanger themselves
and other persons, e.g., by opening the
doors.◀ ...
