A new feature is now available to help support engineers and project admins in their troubleshooting efforts.
The Impersonation option is available through the 
User menu on the UI header bar for users with Admin role. Admins can temporarily change their access rights to impersonate someone else, i.e. to have the same access rights as the selected other user and reproduce their behavior based on the granted roles.
However, the admins cannot grant themselves a role which is higher than their own, and all their actions will still be done under their original name.
The impersonation is valid only in the currently selected project in the current session, and is ended automatically on logout or manually through a dedicated button.
For the specific steps, refer to Impersonating a user.