Add [N-1] Member While Having 3 Time hierarchies

Question

Hi Experts !
I have a technical dimension ([TechDim]) with 1 member ([TechDim].[TechDim].&1). I'm asked to create a new member  [N-1] to represents last year.
in order to manage my 3 [Order Date] Hierarchies, I'm using ParallelPeriod in my code :
([TechDim].[TechDim].&[1],ParallelPeriod([Order Date].[Month].[Year],1,[Order Date].[Month].CurrentMember))
([TechDim].[TechDim].&[1],ParallelPeriod([Order Date].[Week].[Year],1,[Order Date].[Week].CurrentMember))
([TechDim].[TechDim].&[1],ParallelPeriod([Order Date].[Date].[Year],1,[Order Date].[Date].CurrentMember))
But I still have more stuff to add to this code to make it works !
any HELP PLEASE !

Answer 1

I'm trying to do it using SCOPE Statement, my code looks like :
CREATE
MEMBER CURRENTCUBE.[TechDim].[TechDim].[N-1]
AS
// Hierarchy Month
SCOPE ([Order Date].[Month].AllMEMBERS);
 This = (ParallelPeriod([Order Date].[Month].[Annee],1,[Order Date].[Month].CurrentMember),[TechDim].[TechDim].&[1]);
END
SCOPE;
// Hierarchy Week
SCOPE ([Order Date].[Week].AllMEMBERS);
 This = (ParallelPeriod([Order Date].[Week].[Annee],1,[Order Date].[Week].CurrentMember),[TechDim].[TechDim].&[1]);
END
SCOPE;
// Hierarchy Date
SCOPE ([Order Date].[Date].AllMEMBERS);
 This = (ParallelPeriod([Order Date].[Date].[Annee],1,[Order Date].[Date].CurrentMember),[TechDim].[TechDim].&[1]);
END
SCOPE; 
But this code doesn't seems to be correct enough for SSMS :(
Can anyone correct me please 
Thank you in advance