Sequence(thisRow.from,thisRow.to).Filter(CurrentValue.WeekNumber() = thisRow.weeknumber).FormulaMap(CurrentValue.Monthname())
it is the column you use to enter manually the ‘weeknumber’
I need to add something and this is that the Coda weeknumbers are based on USA standards and their week starts on Sunday
the IsoWeekNumber() is the version starting on Monday and this one you might prefer
Sequence(thisRow.From,thisRow.to).Filter(CurrentValue.IsoWeekNumber() = thisRow.Weeknumber).FormulaMap(CurrentValue.Monthname())
hope it helps to get you started this week!
Christiaan