What is the ruling in the matter of traditional dancing in either mixed groups of men and women, men only, or…

Answer

Men's dancing is – by obligatory caution - ḥarām. If a woman's dancing among women is categorized as lahw - e.g. the woman's gathering becomes a dancing gathering, it is problematic and should be – by obligatory caution – avoided. It is also ḥarām if dancing entails sexual excitation or committing a ḥarām act (like ḥarām music/singing), a non-mḥram man is there, or leads to bad consequences.