Team Performance and Process Performance, their reports are based on Teams not based on Roles(Groups).
In some process apps, they require Group rather than Team. So we need to have Team Performance reports based on Groups
In order to base on Group, we need to do do some tricks to trick the process center to capture the statistic of Group.
1. Configure in Process App the team corresponding to the Group, configured in Process Admin.
Ex:

2. Create a Team Filter service, named: AMP Filter Service 2 to force the filteredTeam containing only expected assigned user.

tw.local.filteredTeam = new tw.object.Team();
tw.local.filteredTeam.name = tw.local.originalTeam.name;
tw.local.filteredTeam.managerTeam=tw.local.originalTeam.managerTeam;
tw.local.filteredTeam.members = new tw.object.listOf.String();
tw.local.filteredTeam.members.insertIntoList(0, tw.local.assignedTo);
3. Modify the task in BPD to assigned to a team and with this new filter team service

So the Team Performance can capture the data assigned to user or group(Group contains users).