Create Named Set for Dimension Member in MDX.

WITH
MEMBER [Dim Project].[Project Type].[T&M & FixedBid] AS '[Dim Project].[Project Type].&[FIXED BID] + [Dim Project].[Project Type].&[T & M PROJECTS]'
MEMBER [Measures].[NonBillable Hours] AS
([Measures].[Duration In Hours] ,([Dim BillableType].[Billable Type].&[BILL]
,[DimBillable].[Billable].&[0],[T&M & FixedBid]))
SELECT {
[Measures].[NonBillable Hours]
}
ON ROWS,
[Dim Employee].[Employee Name] ON COLUMNS
FROM [Resource Utilization]