Organization structure and choosing the right profiles

Hi,
I've setup a simple test organization, one department with 3 units.
Each of them is assigned a manager.
The department manager I gave the supervisor profile and the unit managers got the project leader profile.
After entering real work, the supervisor cannot see the timesheet entries of other resources.
What are the correct profiles to assign in order that the department manager can see timesheets of all the underlying resources?

Thanks in advance