Если я правильно понимаю вашу проблему, что-то в этом духе должно сработать (конечно, вы должны использовать правильный уровень, иерархию и имена кубов):
with
member [Measures].[DirectorTemp] as topcount([Salesperson].[Salesperson].members,1,([Measures].[Credited Value],[Credit Type].[Director],[Customer].currentmember)).item(0).properties("Caption")
member [Measures].[Director] as iif([Measures].[DirectorTemp] = [Salesperson].UnknownMember.properties("caption"), null, [Measures].[DirectorTemp])
member [Measures].[ManagerTemp] as topcount([Salesperson].[Salesperson].members,1,([Measures].[Credited Value],[Credit Type].[Manager],[Customer].currentmember)).item(0).properties("Caption")
member [Measures].[Manager] as iif([Measures].[ManagerTemp] = [Salesperson].UnknownMember.properties("caption"), null, [Measures].[ManagerTemp])
select
{[Measures].[Director],[Measures].[Manager],[Measures].[Value]} on 0,
{[Customer].members} on 1
from MyCube