MDX - icCube - How to get a percentage of the Top x on the total using Categories

Question

Following the post on dynamic topcount/toppercentage (see here ) I am looking for an additional row of information showing the % of the Top X in relation to the Total.

So, something like

  create dynamic set [Top 5] as 
      topcount( [Etablissement].[Etablissement].[Etablissement].members, 5, [Measures].[Nbsejours])

*** End script ***

WITH 
 CATEGORY HIERARCHY [Stats].[Top], DEFAULT_MEMBER_NAME = "All Etabs"
 CATEGORY MEMBER [Stats].[Top].[All Etabs].[Top 5 Etablissements] as 
      [Top 5],ADD_CHILDREN=true
 CATEGORY MEMBER [Stats].[Top].[All Etabs].[Autres Etablissements (>5)] as
      SubCubeComplement([Top 5]),ADD_CHILDREN=false

/* This is what I try, but it does not work */
CATEGORY MEMBER [Stats].[Top].[All Etabs].[Top 5 is % of total] as
      [Top 5]/ [Etablissement].[Etablissement].[Etablissement].members, ADD_CHILDREN=false

SELECT
  {[Measures].[NbSejours]} on 0,
  { [Stats].[Top].[Top 5 Etablissements], 
    [Stats].[Top].[Autres Etablissements (>5)],
    [Stats].[Top].[Top 5 is % of total] } on 1
From [Cube]

Unfortunately, I get the error "the tuple expression did not generate a set of tuples or a sub-cube (numeric)."

Is such a thing possible, and how?

Answer 1

The suggestion in the comments above to add a calculated member in another 'not used' dimension worked:

     WITH 
     CATEGORY HIERARCHY [Stats].[Top], DEFAULT_MEMBER_NAME = "All Etabs"
     CATEGORY MEMBER [Stats].[Top].[All Etabs].[Top 5 Etablissements] as 
          [Top 5],ADD_CHILDREN=true
     CATEGORY MEMBER [Stats].[Top].[All Etabs].[Autres Etablissements (>5)] as
          SubCubeComplement([Top 5]),ADD_CHILDREN=false
    /* the hierarchy [Stats].[stats] exists, I add a new calculated member
       to it */
    CALCULATED MEMBER [Stats].[Stats].[Top 5 is % of total] as
         [Stats].[Top],[Stats].[Top].[All Etabs]
    SELECT
      {[Measures].[NbSejours]} on 0,
      {([Stats].[Stats].[default] /* the default member */}* { [Stats].[Top].[Top 5 Etablissements], 
        [Stats].[Top].[Autres Etablissements (>5)],
        [Stats].[Top].[Top 5 is % of total] }) 
      +({[Stats].[Stats].[Top 5 is % of total]} * {[Stats].[Top],[Stats].[Top].[All Etabs]}) on 1
    From [Cube]

The only drawback is that I now get a column in addition.