MTD values are null when Month is selected

[bhaveshp90]

Hello, 

The Expression MTD is showing the correct value as shown in the below image. But when a Month field is selected it is becoming a null value. 

When September-2018 is selected, the value becomes null as shown below

What I am missing in my MTD expression, attached is the file for reference. 

thanks

Bhavesh

[sunny_talwar · Accepted solution]

Change the 

Num(Month)

to

Num(Only({<MonthYear>}Month))

[bhaveshp90]

Awesome thank you @sunny_talwar