I group by 3 columns: Country, State, and City

The data are:

Row 1: US, California, LA

Row 2: US, NewYork, NY 

Row 3: Japan, -, TK

Then, it will be grouped as the following:

1st Group: US (With Subgroup of California and New York, and with 2nd SubGroup of LA and NY)

2nd Group: Japan (With empty Subgroup, and with 2nd SubGroup of TK)

Like WinTree's FreeForm, is there a way to remove the empty SubGroup Row in the 2nd Group?

(Like having Japan -> TK then instead of Japan -> (1) -> TK)

Is there a way to do this???