Hello Luca,

Thank you for posting in our forum.

As I am not sure whether I understand correctly the way you need to transform you data - as far as I see you want to remove duplicate records from your datasource and have a grid with multi-column headers that would contain the months as well as all the aggregated columns for each record? 

I would appreciate if you please provide larger sample datasets in the actual current format and structure that you use - JSON,XML, etc, as well as some more details on why you need your data transformed in such a way? 

This way I would be able to get a better idea of your specific requirements and give you a more precise answer.