MagickPanda
Hi Erich -- this took me longer than I hoped to understand as well.
Checking "Bake Navigation" does do something -- see the docs for TileMap.NavigationLayers
The navigation layers the TileMap generates its navigation regions in.
So, the tilemap is baking those layers automatically into the selected navigation layers.
you could then use NavigationServer2D GetMapPath to calculate a path between two point on the nav layer that has the baked content
https://docs.godotengine.org/en/latest/classes/class_navigationserver2d.html#class-navigationserver2d-method-map-get-path
so in c# if I had a script on a character player I could (after at least one physics frame) get a path between the character's current position and 0,0
var path = Navigation2DServer.MapGetPath(GetWorld2d().NavigationMap, GlobalPosition, new Vector2(), false, 1);
hope this helps!