A unit manager is someone who can carry out transactions on the employees, involved in his/her own branch.
***To be able to choose the employee name for the unit manager access, the employee must have this unit on his/her career page.
The unit managers can do the following transactions for the employees in their units:
Adding a new employee or terminate an employee
Editing every section that belongs to the employee. For example;
A unit manager can add/delete/edit a leave
Adding an asset
A unit manager can see Custom Fields (if you allow him/her from Settings>Access Settings page)
It is optional to show them;
Payment and Salary section
Reports, which belong to their own units
In order to assign a unit manager you can read: How can I assign a unit manager?