How to filter out dates past the current date

Hi! I have one metric here that is using the PREV() function to get data from 4 weeks ago. Hence, the date rows go all the way to 4 weeks in the future here. I have included a widget filter called current_date_flag, which is basically a row in my EC view that checks whether a date is larger than the current date. However, this filter does not seem to be working. Is this because the PREV() function overrides it? Any help would be appreciated!