I'm sorry but the "Team" resources that RTC/RQM/DNG publish to LQE do not include the membership data. Therefore there is no data available to use team member roles in JRS reports for LQE data sources.

I believe the Data Warehouse does contain the team area membership and role data but the Report Builder UI does not expose the necessary types and relationships. In Report Builder, both DW and LQE reports expose team areas as an attribute of a Work Item which can be used for filtering.

However, you might be able to write an advanced SQL query for the Data Warehouse to obtain the data you want but I am not familiar with the tables and columns in the DW where the team members and roles are stored.