Multiple columns from the same dimension table as row labels performing slowly

Question

(Working with SSAS tabular)
I'm trying to figure out what the approach should be for the following scenario:
Lets say we have a Customer table. The table has columns such as account number, department number, name, salesperson, account manager, number of customers, delivery route, etc
A user of the model could want to see any permutation of that information as the row labels. How should that be handled?
What we've been doing so far is that the user adds each column they want into the "ROWS" section in Excel. This works fine with smaller tables (for example, "Department" table with a "Department Code" and "Department Name",
but on large tables this quickly chokes. I understand why this is happening, I just haven't found a better way to accomplish the same thing.
I can add a calculated column to the model through VS, but obviously this is unsupportable and unscalable when each person needs their own permutations of the data. Can something similar be done in Excel? 
This question seems to be what I need:
http://social.msdn.microsoft.com/Forums/en-US/97d1157a-1402-4227-b96a-79524401ddcd/mdx-query-performance-when-selecting-multiple-attributes-from-same-dimension?forum=sqlanalysisservices
However I can't find any information on how to add those properties (is it a multidimensional-only thing?)

Answer 1

Thanks for the help. Sorry but i'm a self-taught developer, and i may be missing some basics :)
Anyway i've done what you suggested but i get this error:
[nQSError: 15011]The dimension table source Dimension Services.DM_D_SERVIZI_SRV has an aggregate content specification that specifies the level Product. But the source mapping contains column COD_PRODUCT with a functional dependency association on a more detailed level .
where:
- DM_D_SERVIZI_SRV is the physical alias for the Service Dimension (and the name of the LTS too)
- COD_PRODUCT is the leaf of the hierarchy, the physical primary key, but it hasnt to be included in the hierarchy
Do i have to add another level with the primary key and hide it to the users?
I tried to solve this going to the logical tables source properties, on the tab contents, setting "logical level" to null for the hierarchy, but i don't know if this is correct.
Thanks