Hi - It can be achieved using the extensibility, There should be 3 levels of extensibility and each cube should assign the respective account in the Cube Dimension settings.
Anything that is common aross all 3 cubes, I put on the parent Cube1 Hierarchy... but my question is really does Cube 1 allow inputs on the lower levels?
Does Cube 1 even see the detailed accounts? and/or does Cube 2 and Cube 3 see the parent accounts defined in Cube 1?
I've built an alt view of the Account dimension (I tried to define relationships across dimensions, but was not able to do so, so instead of a top-down approach, I went bottom-up.
The issues that I encountered were:
1. I could not add Members with the same name to different structures if they were already defined in another dimension rollup (say sibling Dimensions that don't inherit)... I would have to change the member name.
2. I could not add relationships between two different Dimensions (siblings of one another).
3. I could not have a Child Dimension inherit from 2 Dimensions.
So this may work, I'm not sure.
1st Level (Cube 3) - Lowest level
2nd Level (Cube 2) Add some Revenue Accounts and some Cost Accounts
Level 3 (Cube 1) Really the main cube where all data should be visible