I have a Dataset which has 2 hierarchies and a Measure. Brand, Country
and Volume.

Now say my dataset looks like this

Country - Brand - Volume
UK - Brand A - 10
UK - Brand B - 20
UK - Brand C - 30
UK - Brand D - 40
USA - Brand B -30
USA - Brand C - 50
USA - Brand D - 5

Now I want the Total volume of a country depending on whether or not it
has that brand

So (this for Reporting Services) if a user selects Brand B I want to
add together the volumes for all the countries that have Brand B

i.e
Brand B is in UK and USA so the result set would be
Brand B - 185 -> (10 + 20 + 30 + 40 + 30 + 50 + 5)

Where as Brand A would be
Brand A - 100 (10 + 20 + 30 + 40)

The idea of this would be to calculate a Brand as a percentage of the
world but only in the countries it exists. So I could say Brand A has
10/100 (10% of the volume) in all the countries it exists in .
Similarly with Brand B is 50/185 (20 + 30/185)

Does this make sense?

I believe this is doable in MDX and is probably easy when you know how
but I am stuck and am pulling my hair out

Please help

Thanks

Denver