A group transmission device includes a main transmission which has a main shaft, a countershaft and a spur gear pair which includes a first spur gear arranged coaxially and axially overlapping with the main shaft and a second spur gear arranged coaxially and axially overlapping with the countershaft. A range group has a first shaft non-rotationally connected to the main shaft, a second shaft non-rotationally connected to a transmission output shaft, a third shaft and a blocking switching unit. A first switching unit non-rotationally connects the third shaft to a housing. A second switching unit has an axially shiftable switching element and non-rotationally connects the third shaft to the first spur gear. The main shaft is coupled non-rotationally to a transmission input shaft. A third switching unit has an axially shiftable further switching element and non-rotationally connects the first spur gear to the first shaft of the range group.