How to use analysis board & game editor

I see in the comments here I can click on the board icon and the game editor comes up, which I can then use to load a pgn of a game. I also get how to make comments before/after moves. But how do you do those alternate lines things? When you make a move like, 5. Bb4 ?! (5. Bc3 Kf6) Kf6 6 .. and so on.

Also, analysis board is useful for playing around with the game, exploring lines and such, but not useful for saving comments on each move. We can have game notes for ourselves only. Is there anyway to get to the game editor without having to do it in a comment like this?

bump

You just make another move) Just click on the move before the one you want to add, like, in your case 4... a6. You'll get a position before your move on the board. Then you just move a bishop to c3 and it'll be another line. That's it.