I haven't been using Construct 2 for almost 2 years
I don't think that part is right, but to the point layout (by name) is just were you change to a layout by the name of it. Its useful when you want to lower down the amount of code.
In a game I'm making for college it has different levels, so if I name all my levels layouts the same as what it shows inside the game I can use the layout (by name) to save lots of time.
As your layouts are layout1 layout2 and layout3 (I would recommend changing them) you could just have a global variable storing what number layout they should be on then do in the box
"Layout" & layoutnumber[/code:1wj1fvjr]
If you get confused feel free to ask more as I'm bad at explaining things.