Need advice for EPMTUPLE

Hi BPC experts,

Using BPC 10 SP20, I need to display a local member that shows the difference between 2015.01 and 2016.01. This local member must be after 2016.01 ACTUAL such as in the following picture :

My formula is :

EPMComparison(, EPMDIM_CURRENT_MEMBER(ACCOUNT), EPMTUPLE([CATEGORY].[].[ACTUAL], [TIME].[PARENTH1].[2015.01],), EPMTUPLE([CATEGORY].[].[ACTUAL], [TIME]..[PARENTH1].[2016.01],))

I checked the member combination in the report editor and put 2016.01 and ACTUAL.

Unfortunately, it does not work. Is my formula wrong ? Is EPMTUPLE the right formula to use ?

Thank you in advance.

Dat