How to set Q param or FilterCriterion param on Master business object

Summary:

How to set Q param or FilterCriterion param on Master business object?

Content (required):

I have a usecase: For example we have 2 businees object. One is Employee and second one is Department. So there is a relationship, one to many as one Dept and many Emps.

I have to filter data on employees business object upon Emp No, Emp Name, Dept No and Dept Name.

I acheived this on Emp No and Emp Name as these are the direct columns of Emp Business Object using filterCriterion but how can I filter on Dept No and Dept Name while i need