Well... I don't think there's a actual way to clone the entire layout, because if you want the exact same layout to be used... just use the same layout o-o right? I don't know.
But of course, sometimes it's better to copy a few things from a layout to another and then change a few things instead of creating the hole layout all over again from zero.
In this case I suggest you to read a little about layers: https://www.scirra.com/manual/85/layers
You can set the layers with the assets you want to repeat to be global layers, and then make the changes of the layout in a new local layer.
Also, if you want the layout to look exactly the same as the other, just let it be as a empty layout with the same global layers of the other one.
There are quite a few ways to solve this, and it all depends on what you want to do.
Sorry I can't help you more