The DAB+A is made to be used and controlled through a smartphone application. It simply sends the sound to the car through AUX or FM transmission. This is why it is compatible with 99% of the cars, but this is a one way communication, only the sound is transfered. This means that you can only control the sound through your smartphone (by the DAB control app or by your different smartphone applications).
Because you can see all the information in the screen of your smartphone therefore the DAB+A displays in your car screen only the current source that is used (for example BT AUDIO, AUX, BT PHONE).