Step 1) find the manager for each department
Step 2) find the max() salary for the employees of that department.
Step 3) combine the two statements using a subselect
Edit: while looking at the table definitions: that looks very much like the HR schema from the Oracle sample database.
When I look at the table definitions (and the sample Oracle data), there is no such thing as a "manager of a department", so how do you define the "manager of the department"?