Hello Pedro. Unfortunately system administrator accounts are just that, and have access to the whole system. The primary domain administrator should have impersonate rights though, does this not accomplish your goals?

Hi Kyle,

  Since when does a Domain Administrator have access to Impersonate others?  This has been requested off and on for years, and the documentation doesn't indicate he can.

Note: Only the primary System Administrator has impersonation privileges by default. If you are logged in as a secondary System Administrator and do not see the Impersonate button on the right side of the screen or the Manage button when viewing a domain, then impersonation privileges have not been enabled for your account. Please contact your primary System Administrator to request to have "Allow impersonation and domain management" enabled for your account. 

-dave

You're absolutely right David, sorry about that Pedro/David. I was mistaken as I was impersonating the primary domain administrator from the system administrator account. Accessing the primary domain admin account directly does not leave behind the impersonate button. So unfortunately the primary domain admin won't do the trick in this case!

As a workaround, you can give the domain administrator's access to View Passwords or generate temporary passwords for the desired account which would allow a similar access level. We do have an active feature request to allow domain administrators to impersonate, but this has not yet been implemented.