This is just the thread I was looking for! I believe I have found the answers. The two most commonly displayed techniques that I believe a BJJ fighter will use to incapacitate are the single/double leg takedown and the rear naked choke. Check these videos. These aren't new techniques they are just cool minds.
Aikido for Rear Choke and Single/Double Leg Takedown
Enjoy (BTW these vids made me really look into aikido deeper)