Connecting 2 floodlights to 1 sensor

I have put up to 20 lamps on a single sensor, your sensor needs to be able to handle the total current of all the lamps combined. You use the same neutral and ground to the fixture then tap the switched hot, most of the time this is red but usually says load, take those 3 wires to the new fixture and connect them up and now you have your additional light. If exterior to the home in conduit , if you can go back inside and run to the next box conduit may not be needed. Note if you add more wattage than the controller can handle it will let the magic smoke out and quit working.