This is illustrated in this video we did showing off one of the new American Country styles with walking bass lines (starting at 00:33).

Video:- https://www.youtube.com/watch?v=lAGfNFvsUic&t=365s

Notice top left side of screen showing A-1, C-1, D-1 .. etc. These are the 1st 4 standard variations. At 02:04, variation 8 is activated by simply pressign Arr D once more to go from Var D_1 (Variation 4) to D_2 (Variation 8).

So ...

Variation : Screen displays ...
Var 1 = A_1
Var 2 = B_1
Var 3 = C_1
Var 4 = D_1
Var 5 = A_2 (accessed by pressing Var A twice).
Var 6 = B_2 (accessed by pressing Var B twice).
Var 7 = C_2 (accessed by pressing Var C twice).
Var 8 = D_2 (accessed by pressing Var D twice).

Hope that explains.

Thanks,