Calculate different values in one column based on different % that results from another matrix

HI OscarDOSSANTOS,

According to your description, it sounds like you want to get the per month forecast instead of total values. If that is the case, I'd like to suggest you manually process these.
You can get the current year forecast and manually extract aggregate date values on the current cell, then you can use the total month count to calculate with summarized total values. (per month forecast = year total /12, current forecast = per month forecast * current aggregated month amount)
Regards,
Xiaoxin Sheng