Ukrainian: Szczo wy robyly wweczeri?
Belarusian: Szto wy rabili łwieczary?
Is this a mixed group or a female-only group?
The base sentence is "Co robiliście wieczorem", so it's 'at least one man' group. Then "robiłyście" is for female-only group, "robiłeś" to one man and "robiłaś" to one woman.