Again this is just a sample and the actual expression might be more complex (instead of Sum(Value) if it was Sum(Aggr(FirstSortedValue(Aggr(Sum(Value), Date), -Date), Date, OtherDimensions)) or something)... would you still want to do this in the backend?
Depends on the requirement; If target expression where he needed non zero values of row above look like the one you have shown, I would first get additional field with that complex expression and then would apply the same logic on that field
Sounds good... I thought your expression was complicated and that is why you wanted to do this on the front end. If that's what you need. I suggest marking his response as correct and close this thread