This has been discussed so many times, that we have this Sticky at the top of the Semantic Layer forum.
If your users don’t let you use aliases in the way they were intended, they’re asking for trouble. They’re part of the product in just the same way as you’d alias a table in native SQL, if necessary, in order to use a reference/dimension table for different purposes.
How would you solve this sort of problem in native SQL?
Anita Craig 
(BOB member since 2002-06-17)