They did Nazi that Coming: Achievement STEAM of Wolfenstein 2: The New Colossus

There are always opportunities for sneak kills when commanders are nearby. The easy way to get this is by making a manual save after every stealth kill. If you get detected, reload the last manual save. This way it will keep your stealth streak. You have to stay crouched and sneak up to enemies from behind to perform a melee kill (10 times in a row).
This cannot be farmed via checkpoint restart.