Can attribute relationship help in providing different results?

Hello All,

   Have come across something very interesting.

Am having a natural hierarchy [ICD 01]>[ICD 02]>[ICD 03]>[ICD 04] like below

However am trying to do a cross join of the attributes instead of using the hierachy.For my query below its calculating currentmember/currentmember.parent ie All member of that attribute . which is correct.

MEMBER [Measures].[Rx Count Pct] AS 
' IIF ( [Diagnosis.ICD 03].CurrentMember IS [Diagnosis.ICD 03].Levels(0).Members(0),  
IIF ( [Diagnosis.ICD 02].CurrentMember IS [Diagnosis.ICD 02].Levels(0).Members(0),
 ([Diagnosis.ICD 01].CurrentMember, [Measures].[Rx Count]) / ([Diagnosis.ICD 01].CurrentMember.Parent, 
 [Measures].[Rx Count]), ([Diagnosis.ICD 02].CurrentMember, [Measures].[Rx Count]) / ([Diagnosis.ICD 02].CurrentMember.Parent, 
 [Measures].[Rx Count])), 
 ([Diagnosis.ICD 03].CurrentMember, [Measures].[Rx Count]) / ([Diagnosis.ICD 03].CurrentMember.Parent, [Measures].[Rx Count])) ' 

Now when i change the attribute relationship to something like below.

For the same query.

It gives me currentmember/related member from the level above it from the hierarchy.

Can anyone please example the situation here.

THank you!!

Regards,

Bharath