Hi Praven,
We have a very new feature (I think not visible until the next field
test) that allows you to say that one level depends on another level,
for *exactly* the reason you want here.
In the level definition (only in Studio, I think), you include
something like
dependsOn="[otherdimension].[hierarchy].[level]"
This adds a combined index to the fact table that we use when we
retrieve members. The modeling guide in the field test will have
details and (for demonstration purposes) will show how to modify
SAMPLES to see this feature. It's pretty simple to do though.
So stay posted!
Cheers,
Lexi