Manager's team calendar - hierarchy permissions to see details from top-down

Hi, I have a question about Manager's team calendar and how it's supposed to work. 

The manager would like to see all the details of the calendar events of who report to him, but currently by default the manager can only see "free/busy".

Idea is to make the org hierarchy work by equal level people not see each other's details, only free/busy, which works right now, but the higher level manager should see everyone's details under him. Hierarchy is already set-up correctly.

Is that possible? If yes, how?