User hierarchy question

I'm going to be developing a site that needs a user hierarchy with specific content access control. Basically, it's going to be for managing product certifications.

Let's say 10 companies use this site for certifications. A user will log in, access content based on his role and complete a certification. I also need a user manager to be able to see this user and what he has completed, but not edit the profile.

This is pretty straightforward I think with views and content-access, but how can I grant the user manager for each company access to only their users and not all users?

I'm not a very experienced Drupal developer, but I've emersed myself in it over the past couple weeks and I think I'm almost past that initial learning curve.