Proper way to pose the question: کیف أستخدم هذه العبارة ؟

If there were more than two people use بعضهم البعض = one another If they are only to persons use أحدهما الاخر = each other

بعضهم البعض ( ba3duhum alba3d) means something like "each other" examples: أحَبُّوا بعضهم البعض ( ahabbu ba3duhum alba3d) they loved each other كانوا يضربون بعضهم البعض ( kanu yadribuna ba3dunhum alba3d) they were hitting each other. hope I could help :)