Sales, marketing, legal in every market they operate in. Remember they don't have to deal only with different countries, but different states and municipalities in each of them, each with their own laws and ordnances and lobbying needs.

They have a presence in every country they're active; likely a big chunk of it is customer services, both for consumers and drives. Administration as well, they are handling a lot of money after all between a lot of people. See https://www.uber.com/us/en/careers/ for what positions they hire for.