I'm trying to make my Navmeshagent find it's way to any selected location of my choice (From a drop-down list). I got that part working. But now I want the agent to navigate through waypoints. In detail, I want a scenario where when I select a particular location, the agent goes to that location only through the waypoints specified on that path. 
In the images above, Sophia is labelled 1, while Rachel is labelled 2. My agent is moving from Sophia's location (as selected from the 1st drop-down), to Rachel's location (2nd drop-down). I want to make a waypoint system where the agent can only go to these locations through the waypoints on each path. And will automatically know which path(waypoint path, if you may) to use once a location is selected.
PS: I haven't started anything about the Waypoint system yet cus I don't even know how to start