Just drive it until warm and press the button on the end of the indicator stalk (left). Cycle through the displays until you get the oil indicator. You will get the measurement while driving.
If your are stopped you may see the little clock ticking down for a few minutes before it shows the measurement.
The engine must be hot.
E92 M3, Competition Package, MDCT, Ground Control Adjustable Camber plates, StopTech 380 BBK, OEM exhaust mod