The Expression is working for selections on Year and Month
However it doesn't show the correct answer when the Day1 field is selected. (But it does work work when 2 or more Day1 fields are selected. It then shows the value for the MAX Day1 field selected i.e. if Day1 value like 2 and 10 are selected then it shows the value of 10th, but if only 10 is selected then it gives the wrong answer).