Expression doesn't work as dimension

[#1]

Any idea why the below expression is returning //Error in calc... when I put it in the dimension?

Alt(only({<[Classification Source]={'$(=[Classification Source1])'}>}[Asset Classification (1)]),

  only({<[Classification Source]={'$(=[Classification Source2])'}>}[Asset Classification (1)]),

  only({<[Classification Source]={'$(=[Classification Source3])'}>}[Asset Classification (1)]),

  only({<[Classification Source]={'$(=[Classification Source4])'}>}[Asset Classification (1)]),

  only({<[Classification Source]={'$(=[Classification Source5])'}>}[Asset Classification (1)]),

  'NULL_CLASS')

Class Source1-n above are islands which are user selections.

[whiteline]

Hi.

Because you have to use aggr() function for calculated dimension.

[Anonymous]

I suspect there is a better way to handle your situation, but if you prefer this way, try to use aggr() around this expression:

aggr(

<your expression>

, [Asset Classification (1)]))

[#4]

the aggr() works except it doesn't populate 'NULL_CLASS' for nulls.  Would definitely be interested in a better way to handle this if you have any ideas.

EDIT: This actually doesn't resolve the issue.  It generates values for the dimension, but when I switch to a pivot, it does not group the like values together.

[Anonymous]

A better way is to create an actual dimension in the data model, if possible of course.