If the lowest level of detail is job title and starting from scratch:
Put employee on rows.
Put Job Title Identifier to the right of Employee on rows.
Create a calc of size() > 1
put that calc on the filter shelf. Compute using Job Title. Set to true.
All Employees with only 1 job title will be "hidden" from the results.
I'm making assumptions about your data structure. If those assumptions are incorrect then the solution might have to be approached differently.