as I do on a graph that has a dimension cyclic group containing year and two months to make different calculations.
How could I do to select year when he makes a speech and when selected another month's calculation.
You can use the getcurrentfield function to retrieve the currently active field in the cyclic group. Something like this:
if(getcurrentfield(MyGroupNameHere)='Year', ...year_expression..., ...month_expression...)
See attached example.
Retrieving data ...