Moveable navmesh

[charred shadow]

So I heard that unity got an official moveable navmesh feature. But there is absolutely no documentation on it, all I could find from googling is an old tutorial video showing how to make a moveable navmesh for an old version. Obviously this tutorial is obsolete if unity has recently got its own feature for this.
Is it an actual feature (and which unity version was it added in?) and how does it work? How to make it work? Because there isn't any documentation available on it.
Thank you!