SSAS : Using drill through action to collapse by an MDX condition - ssas

Question

I have a ragged user hierarchy,with a custom internal hierarchy within the dimension, called [Dim User].[User Hierarchy] which is based on a denormalised Level1, Level2, Level3, Level4, Level5. What I want is that the user hierarchy is collapsed based on a condition that the user type of a descendant of user type SHOP.
What I have done is created a drill through action, with this condition :
IIF([Dim User Balance].[User Type Key].CurrentMember IS
descendants({[Dim User Type].[UserTypeIdHierarchy].&[9]},0,self), TRUE, FALSE)
However when I try to access the drill through action, I cannot seem to find it anywhere? What am I missing? Or maybe is there anyway better to do this?
When trying to do this with mdx, this query is leaving out members :
SELECT
{
[Measures].[Measure]
} ON 0, non empty {
FILTER (
{[Dim User].[User Hierarchy].[Level1].allmembers }
,[Dim User].[User Hierarchy].CurrentMember.Children.Count > 1
)
} ON 1
from [cube]
And when doing it like this:
SELECT
{
[Measures].[comp money in]
} ON columns,{
descendants( [Dim User].[UserHierarchy].children,0,self) *
descendants([Dim User].[UserTypeIdHierarchy].&[9],0,self)}
on rows
from [activities]
It is excluding the descendants of the user hierarchy in the measures, which is not what I want. I want all figures still to be aggregated. It is what I display on my Y axis that I am concerned of. I want it focused on specific user types, which are descending from 9.