Want to sum a value based on a max date

[#1]

This is going to be easy to most people but I'm new.

I want to sum(value) where DaysFilled.Date=Max(DaysFilled.Date)  and also $ current selection.

Thank you!

[#2]

try this:

sum({$<DaysFilled.Date = {$(=Max(DaysFilled.Date))}>} value)