Same Customer Growth

I currenlty am using time intelligence to show YOY Growth.

We add a lot of new customers each month, and I need to make this a true like for like growth representation for the business. Is there a way that I can add a flag or DAX to only include sales for units that exist in both time periods selected? 

If I selected "X" months data, I'd want to ensure that only customers returned had results in all "X" months (This Year + Last Year).

So if I choose 2017, I'd only want customers that have sales in all periods of the same time frame last year to be included as well.

Hope that is enough of an explanation. 

Thanks!