Dennis - you can add another server instance and in the NAS ID, add the second eSSID (name of the SSID).
Add another server group as well and place the new server instance into it.
Edit the existing NPS server and add the old eSSID to the NAS ID.
Next, add a new VAP and apply the NEW RADIUS server group to it.
The NPS server can now distinguish between the SSIDs by looking at the NAS ID. The NPS policies can treat the two SSIDs differently.