Just use Go to layout by name and enter choose("level1","level2","level3","level4","level5")
You just need to name your layouts correctly.
Or you can have a text variable with that choose() and enter the level name there.
This will load one of those layouts randomly.
Use this (from the layout selector layout?) when you want to go to a random layout, change the names appropriately.
So when you click your level one have 5 level names in there, for your level 2 add 10 names in there etc.