Birds of a feather flock together
sfuj dɔ sfɛɡɔ tɕɔŋɡɲʲɛ
In Polish Swój do swego ciągnie.
This Polish proverb means 'One's own draws to one's own,' meaning people of similar backgrounds or interests tend to associate.
Example
"Oni zawsze razem, swój do swego ciągnie."