How to create a formal that shows data from what you select on the graph?

[Noor51]

I trying to create a table when a user select a month on a graph it shows the select month, pervious month, and the variance between them. The expression I use doesn't pick up the month, and I don't understand why. Can someone explain it to me.  (CM mean Current Month)

[Chanty4u · Accepted solution]

Try this 

Selected month 

Sum({<Month={'$(=Only(Month))'}>} Amount)

Previous month 

Sum({<Month={'$(=AddMonths(Only(Month), -1))'}>} Amount)

For variance

Sum({<Month={'$(=Only(Month))'}>} Amount) - Sum({<Month={'$(=AddMonths(Only(Month), -1))'}>} Amount)

Please modify your fieldnames accordingly in above expression i have given sample example