While the documentation clear states:
"The EPM Framework version 3.0 will support nested server groups defined in the Central Management Server. Note in
Figure 9 that the group “Production” has three nested groups. When a parent group is used as the parameter –ConfigurationGroup, all instances registered to the parent group and all instances registered
to child groups will be included in the evaluation."
It doesn't take into consideration the user wanting to evaluate policies against ONLY a child node. I struggled with this problem for a few minutes until, after reading about the errors throw by the previous version that didn't support nesting, I noticed
it would not be a '\' but a '$' required.
That is, if I have a parent named "Production" and a child named "US", I refer to the ConfigurationGroup as "Production$US"
Thank you Lara for your fantastic work - it's been a massive help!