Visualize Rolling 12 Months

Hi Everyone, 

I've spent about two days researching how to accomplish this, reading articles both on the PBI forum and also external articles. I've attempted to solve this myself using some DAX others shared, but I'm still not able to accomplish what I'm trying to achieve. 

I have a dates table that's already set and built quite extensively. It's also set as my date table in PBI. [Dates]

I have another table with row by row employees who've terminated and within the table a date of when they were terminated. [EE Details] 

I've sucessfully written a dax called MoM Terms, which calculates total terms by month, and I've sucessfully visualize it as such and use that dax on other plots. [MoM Terms] 

I'm trying to visualize using a bar chart the rolling last twelve months (not including current month). This is what it looks like: 

As you can see, it's still including March 2020, though I didn't check off include today. ;( 

What I'm really trying to achieve is the following: 

Any thoughts on how I can do this? 🙂 Thanks so much! 

Nabsters