Birds of a feather

In English: Birds of a feather flock together. -- People of the same sort are usually found together.

In Spanish:

(In Argentina) "Dios los cría y ellos se juntan."-- God creates them and they get together. Alternatively: "Dios los cría y el viento los amontona."-- God creates them and the wind blows them together.

In Portuguese: Diz-me com quem andas, dir-te-ei quem és.

In Russian: Рыбак рыбака видит издалека. - Fisherman sees another fisherman from afar.