Controlling object focus

I know from reading other posts where folks are trying to control tab order, that Storyline doesn't allow much (if any control over tab order). However, I am wondering if controlling object focus is possible via variables, triggers, etc.

Goal:

I am trying to get the the focus to jump from one (in a series of four) button to an object in a layer made visible by clicking that button. Conversely, when the user clicks the close button on the layer, the focus would be forced back down to the button that triggers the layer visibility.

I will continue trying to solve this in the meantime. If I do, I will be sure to post the results here.