What is the knob in the middle of BMW x3 cup holder?

The circle next to the BMW x3 cup holder is the Idrive operation knob, which is mainly used to control the CID central display screen, operate the relevant settings of the vehicle, information retrieval, navigation, audio operation and so on. That disc is actually the main control knob of car multimedia, which can be rotated and clicked, or the shift paddle behind the steering wheel, freeing the place where the shift lever was put before and designing it for other purposes.