Hi,
EMPDIM_CURRENT_MEMBER(SOME_DIM) returns the cell reference with current member of the dimension SOME_DIM - for row or column axis. There is no formula to get a reference of previous member, but you can use the following:
For member in row axis:
Assuming that previous member is located in previous row:
=INDIRECT(ADDRESS(ROW(EMPDIM_CURRENT_MEMBER(SOME_DIM))-1,COLUMN(EMPDIM_CURRENT_MEMBER(SOME_DIM))))
Vadim