Doubt About Inspector Buttons

Hello. I saw an youtube video about a 3D Tile Editor, so because I need it, I decided to do a similar editor. My doubt is how to program a script who does this type of inspector button, not the logic inside it, just the button and how to apply to it the respective action.
Thanks.

Ps.:

The video link: 3D Tile Map Editor in Unity

maybe…There was no direct button ref for the Editor. It looks like you create buttons using GUI.Button

HTH
BTH

Ok.

Maybe he can charge some external database file right? And the main script loads this new information.

So, other question: I need to build a tile map, square based, any hints for this system? I was thinking about, cubes and a database file with data matrices, a 3D matrice with X,Y,Z axis, and a minimal distance to every tile cube. Is it appropriate?