Conversation so far:
When did Josef Mengele join the German military?
Josef Mengele was called up for service in the Wehrmacht in June 1940, some months after the outbreak of World War II
What was Josef Mengele's rank?
Josef Mengele served with the rank of SS-Untersturmführer in a medical reserve battalion until November 1940
What did Josef Mengele do after 1940?
Josef Mengele was next assigned to the SS-Rasse- und Siedlungshauptamt in Poznań, evaluating candidates for Germanization.
What is the process Josef Mengele was involved with called germanisation?
Germanization, is the spread of the German language, people and culture

Question: What else did he for that office?
Self-contained rewrite: What else did Josef Mengele do for SS-Rasse- und Siedlungshauptamt in Poznań besides determine who was fit for Germanization?