Layout:
Layouts contain a stack of layers. Objects that appear on the screen do not belong directly to a layout - they always sit on one of the layers in the layout.
A layout for me at least is a container that holds all the layers.
Important. Layout has event sheets.
layer:
Layers are like a piece of glass that user can see through.
HUD (top layer - health bar, UI info etc.)
Foreground (main game objects)
Middleground (a parallaxing background layer)
Background (bottom layer - the background)
A menu on a layout is something that a user clicks and leaves current layout and goes to menu screen, option screen, save, load screen, help screen etc.
Layouts are also nice for different levels etc...
To answer your question:
Have a button that when user clicks takes him to another layout (found in system) called goto layout.
That makes user leave current layout and go to menu.
That is the reason for on start of layout this loads all the user info back. I put seperate event sheet that handles this, and include it into the on 'start of layout'
So if your menu is seperate layout you can't have it show up on another layout.
Well, you can have a snapshot of your layout using the snapshot canvas (I don't know how to do this), I don't know if that is how it works. I am guessing here.
So layouts can't be shared.
BUT,
Layout1 with 150 layers. THose 150 layers can be activated / deactived. Made visible etc. Which is why I went that route.