A new Beta Linkage program is here (click this text).
In the above video, you can see two links rotating in circles and always overlapping. Each link has three connectors, one at each end and one in the middle. I added a three connector link near the intersection point and then set two of the connectors to slide between the ends of one rotating link. I set the remaining connector to slide between the ends of the other rotating link.
If the exact point of intersection needs to be “tracked”, add a guideline and set it’s ends to be at the ends of one of the rotating links. I used the rotating link that has the two sliders on it. Then drag the other slider to the intersection point. it should snap to the exact intersection. Having to add a guideline is a bit of a pain but snapping to the intersection of two links isn’t yet available in the software.