How do you scroll multiple Button Symbols(interactive content)?

Hi, I’m having a lot of trouble trying to figure out how to make multiple buttons (my content) scroll through an invisible scroller that works on rollover. I’ve figured out how to make text and movie clips scroll but not buttons. Please help! Heres a site that I found that is doing something very similar to what I ultimately want to achieve: (I hope this gives a better idea of what I’m talking about)