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.