For a single dimension (e.g. LOCATION)
sel LOCATION *
set mea3 nocon
set mea1 nocon
set mea2 nocon
calc mea3 = mea1 * mea2 / mea2 of COMPANY TOTAL_COMPANY full
I have not done this for multiple dimensions so you'll need to experiment with the syntax. I would guess something like.
calc mea3 = mea1 * mea2 / mea2 of COMPANY TOTAL_COMPANY GEOGRAPHY TOTAL_GEOGRAPHY full