How to call Navmesh Bake from Editor Script?

Hi guys!
I’m a rookie. i have a problem in Unity3D but i don’t know how to solve! Can you help me, please!
I have two map and one character moving on it (two independent map). The maps selected by click Menu.
I want to make character moving on two maps at two different times (click menu>selected map). But I can not because I only bake navigation by hand. So I want to call Navmesh Bake from editor scripts or somehow help me make that my idea, please!

Currently it is not possible to build a navmesh at runtime without using packages from the store or writing your own navmesh script entirely. However the functionality is coming soon. Check the Unity Roadmap and look for AI:NavMesh workflow and bake API.

This was previously listed as being scheduled for version 5.5 with a predicted release date of June 7th however it now seems to have gone into alpha and doesn’t state a predicted date. Hopefully we will get it soon.

Personally I am waiting for that to be released rather than spending any time building alternative solutions to the problem.