Triggers

I'm not quite sure what you're wanting to do. However, looking at your file there are a few pointers:

• if an object has a visited state (like your buttons) you don't need to create a trigger to change state to visited because that's what a visited state is. Storyline changes the state automatically.
• to go back to the base layer, all you need is a trigger to hide the layer, you can add that to any of the buttons
• keep in mind that base layer objects are visible on all layers unless they're covered up;
  • you can make base layer objects hidden if you go to the timeline while in the layer, at the bottom you can expand and show base layer objects and select them to be hidden or visible;
  • you can also open the layer properties and select hide the base layer objects (which is what you have done, I believe)