Dax to calculate 2018 Sales Forecase (resolved)


This question is regarding the scenario analysis training video.

  1. Dax to calculate 2018 Sales Forecast
    Question: I would like to need some help to understand how the filters function in below DAX formula works to copy 2017 Total Sales and write them as the 2018 Sales Forcast for rows of 2018 only. Thank you.

2018 Sales Forecast = Calculate ([total sales], Filter ( All(dates), date[Year]=2017, dateadd(dates[date], -1, year))


I think that I understand now and this is resolved. Thank you.