YOu can use the Insert Summary (Sigma sign in the upper left corner) function and have it count any field and reset on the group.
Likely you want a count of calls per employee so do a Count on any fiel dfrom Calls (if there is a PK use that and do a DistinctCount) with the Summary Location as G#2.
If you want a count of all calls per department do the same thing but make the summary location G#1.
For all calls int he report same thing but location is Report Footer.