Group selection isn't natural but human tribalism almost certainly invokes it. Much harder to get kicked out of a tribe than out of the gene pool, meaning tribes as a unit would naturally decay together, thus get selected as a unit.
Individual selection for being a good tribe member is absolutely present and significant. More advanced tribes set up rules that you had to follow and if you failed you were hung - then displayed as a warning to others. Strong selective pressure there https://en.wikipedia.org/wiki/Gibbeting