To have a single Paradigm Light Sensor monitor primary and secondary daylight harvesting zones, you will need to add a remote sensor head. The remote head's wire pair will land on the header labeled 'optional sensor' on the main sensor's PCB. Once the remote head is wired in, the sensor will immediately begin to listen to monitored values from both heads and create an averaged reading. Program the sensor as usual in LightDesigner, there is no need for additional programming since this functionality is coded directly into the unit's firmware.
Unison Paradigm Responsive Light Sensor Installation Guide (references the remote head and how to wire it in)