How to track down a business' real address so I can serve them with papers in small claims court?

I'm trying to take a former employer to small claims court for not paying me some money they owe me. I know they moved, but it's been difficult to track down what office they're really working out of. They have an address posted online, but I seriously doubt they are really based out of this location--it's very high end. Is there an official way to find out a business' real operating address?