In-cockpit compass - how to use it?

[Raven Morpheus]

Hello

Just done a QMB flight and I noticed that I've turned off that little line on the map that tells you where your next waypoint is, presumably by setting realistic navigation to on.

So, this is probably something I should have learnt a long while ago, but with realistic navigation set to "on" how do I use the in-cockpit compass to tell where waypoints are?

Thanks.