I assume you are talking about the two lights inside the DS slide.
I've not had to trouble shoot anything there yet, but if it were mine, I'd first get out my trusty voltmeter, and see whether there was any voltage at the fixtures.
It's possible that both light bulbs went out or are unscrewed, might not be the most probable but that's an easy check.
Next I'd open the bed, and check the wiring under the bed and behind it where there is a bundle of wires that move with the slide. Look for something that either came loose, or was pinched.
I believe the power comes from the hall spider panel, connector 3-2 or 3-3. Check the spider breakers to see if popped. If not, then you can unscrew the spider panel and with your voltmeter, check whether you have voltage on the 3rd connector, pin 2; and/or 3-3.
Figuring out where you have power, and where you have dropped power, will lead you to the solution.
DaveB, Raleigh, NC
2015 Tiffin RED 33AA, w/Honda CRV
VMSpc, Magnum BMK/ARC50