In this situation if you want to do something completely different depending on the layout, you really ought to have two different functions. The old Function plugin only allowed this usage by accident, and I really think it's a poor way to structure your events - for example if you look at a "Call function" action, you can no longer tell what that does, and "Go to function" can't work - it depends on which layout you're on, which also involves reviewing the tree of event sheet includes across your project, which is hard work. If you just call a different function it's much more obvious what it does.
How to better structure the events depends a lot on the details of your project. If you have a "common" event that really needs to call two completely different functions, I'd argue that is not actually a common event and ought to be implemented as layout-specific logic. This will involve rearranging the whole way those events are used, but I think it will be much clearer afterwards. Alternatively a quicker (but not particularly elegant) approach is just to have a global variable with the game mode that you set on each layout, and dispatch to different functions depending on the mode. I'd avoid relying on the layout name, because people normally expect to be able to rename things without breaking anything, and you end up in the situation where you can accidentally break your events just by renaming a layout.