When an FM station has a corresponding DAB station, and vice versa, they can often be linked in the radio app. Linking the two radio sources allows the car to automatically switch between the DAB and FM stations to play the source with the strongest reception.
Press the app library symbol 
in the bottom bar and open the radio app.
in the bottom bar and open the radio app.Press the settings symbol 
to go to radio settings.
to go to radio settings.Turn DAB and FM linking on or off.
When turned on, the radio app shows one radio station tab.
When turned off, the radio app shows separate DAB and FM station tabs.
Note
It might not be possible to link some corresponding DAB and FM stations, so these will appear as separate stations.