OTBI Report showing highest degree level

Summary

Has anyone figured out how to create a report on degree information where the employee is listed under only their highest degree?

Content

I have a requirement for a highest degree report where employees are listed by highest degree level - doctorate, masters etc.  I have been able to use case when/bin logic from the person profile subject area to return all degrees and to group degrees into their respective levels, however, I have not been able to figure out how to display just the highest level when an employee has more than one degree.  Does anyone have any idea on how I can accomplish this in the BI tool?  We have a data model based report, but it is timeing out when incorporating