They were used in the African and the Middle-Eastern theaters against other colonial troops. They weren't used in Europe again because, as I mentioned, when the British tried to employ them on the Western Front the Gurkhas performed atrociously. They did do better in WW2 but again, most of their fearsome reputation comes from fighting the Japanese not from their exploits in Italy and Greece. Wehrmacht didn't think they were anything particularly special. Even today Gurkhas are basically used by the British as glorified guardsmen. Better than the rest of their subcontinental brethren but not by that much.