I'm confused on BungeeCord

Ok so I recently just got BungeeCord, and im trying it out to see if it works. It worked correctly the first time on some random servers I made. I'm also running the servers from my computer so they all have the same IP. And I have a different domain from dot.tk on the server im currently working on (that is also run from my computer). So how do i connect the .tk server to a different server that I am running from my computer? The help would be really appreciated.

Thanks,
Faze