I cannot see the documents of a team member - why?

I need help finding another team member's documents

If you cannot access the documents of a team member, the owner, or the team's admin, you are not granted the permission access level to see their documents.

Contact the team owner or admin and request the needed permission from them. 

I want to see the documents of a team viewer

You cannot see the documents of a team viewer, even if you are both teammates on the same team. Team viewers can see enabled documents, but only the team owner and admins can access their documents.

You can read more about all types of roles within a team here.