Sami swoi (1967)
Sami swoi (variously translated as All Friends Here or Our Folks; literally "Only ours") (1967) is the first part of a Polish comedic trilogy of movies by Sylwester Chęciński. Its two follow-ups are Nie ma mocnych (a Polish idiom meaning "no can do") (1974) and Kochaj albo rzuć ("Love It or Leave It") (1977).
More at Wikipedia.