One of the shortfalls there appears to be with Tableau is how to work around the inability to create custom hierarchies for SSAS data sources.
I understand that the idea is to push back this into the cube, but this does end up presenting a couple of issues.
The first is that by default, SSAS does not let you build hierarchies with attributes from separate dimensions, so unless I get funky and use my fact table to create this, it aint gunna happen. Wondering if this is how others have handled this.
Along the same lines, we were hoping to create a user definable hierarchy where the user could be presented with two or more pairs of drop downs which allow them to select attribute and attribute member for each.
For the SSAS datasource, I think at absolute best this could be done for attributes in same dimension but would be interested in getting any feedback from someone who has tried to do such a thing.
I know that we are trying to provide fixed report that gives ad-hoc ability which is maybe trying to do too much so I am managing my users expectations ;-).
Self service is obviously the way forward and is on our roadmap, just a bit of a way off still!