A vehicle, a vehicle display device, and a method for controlling the vehicle display device are disclosed. The vehicle display device includes a display unit and a controller. The display unit displays a wide screen that is divided into a main display region and an auxiliary display region. The controller displays a first visual interface on the main display region, decides the second visual interface for performing a process different from that of the first visual interface according to the first visual interface, and displays auxiliary information related to the second visual interface on the auxiliary display region.