I will be flying SCL-GRU via Swiss Air business class, I then have approxiamately 5 hours to cool my heels before boarding a UA flight to IAD. I've heard that the GRU terminal is extremely confusing and difficult to navigate. Are LX and UA in the same terminal? How does immigration work?

Also, what can I do for 5 hours in GRU? I am *G so perhaps I can hang out in a lounge - any recommendations?

Thanks for your help in advance!