Yes, it's fixed now. Thanks.

Yes, I agree with you. But can you tell me how to fix that? I create the hiearachy, but why it doesnt work?

The attribute relationship is fulldatekey ->Month Name->Year

Thanks

You can try the solution from Darren Gosbell

Usually I have a column for MonthName and another for month number using a YYYYMM format that looks something like the following:

MonthName ...