Past 12 months dynamic

{StrToMember("[Kalender].[J4MND].[Jaar 4MND Maand].&["+Format(DATEADD("M",-1,now()),"yyyyMM")+ "]").Lag(11):StrToMember("[Kalender].[J4MND].[Jaar 4MND Maand].&["+Format(DATEADD("M",-1,now()),"yyyyMM")+ "]")}