Hi Ajay,
I am seeing that there is syntax error in your code (bracket mismatch). It should be;
IF
([CubeName].[Dimension].[Dimension]->?PromptMonth? = 'Oct')
THEN
([CubeName].[Dimension].[Dimension]->:[TM].[Dimension].[Dimension].[@MEMBER].[Oct YTD])...
I am seeing that there is syntax error in your code (bracket mismatch). It should be;
IF
([CubeName].[Dimension].[Dimension]->?PromptMonth? = 'Oct')
THEN
([CubeName].[Dimension].[Dimension]->:[TM].[Dimension].[Dimension].[@MEMBER].[Oct YTD])...