Check ASO cube for data and delete members whci have no data

We have a BSO cube (Ex:BSO1)  with has current month data and metadata , 3 (prod, lot,key )dimensions in this BSO1 and dropped and built each month  .We also have  a corresponding reporting ASo cube (ex: ASO1) Here we merge all the current month data and metadata , Because of this in the ASO1 cube 2 of the dimensions (lot and key) are rapidly growing in size . We are planning to create another archieve ASO cube (ex:ASO2) where we would like to trasfer all metadata older that previous year  and the Current cube ASO1 will only have previous year