I wish to build a calculated measure who's value is the percent of the total
for a given measure.

For example I have a dollars measure. I want a measure that is "dollars
share", which would yeild dolllars/"total dollars".

I have a measure that will do this properly with respect to a particular
dimension, but I wish to have a generic measure that will work regaurdless of
which dimension I slice it by.

Here is the query that works for a dimension "Brand"

[Measures].[Dollars] / ([Measures][Dollars], Ancestor([Brand].CurrentMember,
[Brand].[(All)])

this calculated member works for brand, but if I try to use another
dimension it does not automatically switch to that dimension.

Is there a way to do this?

Thanks.