Modifying DAX Code for retrieve full data

Hi there,

Below is the sum of Sales with 

LLM last last month, LM Last Month, TM This Month

Hope my result like:

1st approach:

Right now i can retrieve the result by selecting Billing Month. 

Without selecting Billing Month Error Message: A table of multiple values was supplied where a single value was expected

2nd approach:

Its not working since i have to use month as one of my parameter.

How can I modify the code so that I can have a full picture without selecting Month.

Thank you for your help.

Sammy Chu