In the "Tracker" window, there is a pulldown labeled "Current Track" and for me right now it has two choices: "Tracker 1" and "None".
I have a clip with five or six dancers that take turns dancing and I have tracked the first dancer and wanted to start a second track for the second dancer. In this particular case, I figured out that I don't really need or want to do this because the dancers cross paths and I can just reuse the same "Tracker" for each girl. But, I would still like to know how to create a second "Tracker".
So far, all the YouTube videos and web pages hasn't address this question. I predict it is drop dead easy and right in front of my nose.
In the tracker panel, click the Track Motion button again. This creates a new Tracker. I suggest renaming the Tracker by pressing the Options button on the bottom right of the panel. Basically everytime you click the Track Motion button it creates a new tracker.
Keep in mind each tracker's track point will still be named Track Point 1.
Multiple track points can be added to a tracker to track additional properties beyond just position.