Normally MDX queries are returning caption for reports when we are using data in SSRS. But we need other information such as UniqueNumber and other when passing as parameters to other reports and datasets.
Below shows example query used for get the member properties. (We can declare it using WITH MEMBER). DayKey is the custom column we are creating
with member DayKey as [Date].[Date].currentmember.uniquename
SELECT NON EMPTY
} ON COLUMNS,
} ON ROWS FROM [RetailigenceBI]