Waterfall Forecast with Accuracy Percentage question(s)

[Knoble]

I have a dataset that I need to create the following in Power BI.

I built out the excel file and imported it like this, but now I'm feeling like I either didn't set it up accurately, or there is a step I am missing to get the percentages to look like the above (the forecast date is the forecast version and each group has to provide a fresh forecast each month).

This is the output I am getting, the up to 30 days out is matching, but everything else is wrong. I would appreciate any and all assistance.

I would also value your thoughts in how to establish a 30, 60, and 90 day slicer.

Thank you

[v-xianjtan-msft]

Hi @Knoble 

Sevenhills' reply shared a wealth of reference resources, did it help you solve your problem? If yes, please consider accepting sevenhills' reply as a solution, which is helpful for other users seeking answers to similar questions.
If you have any other questions, please feel free to contact me.

Best Regards,
Jarvis Tang
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

[Knoble]

It's good information, but it would have been nice to get a better walk through. 

[sevenhills · Accepted solution]

I believe what you are doing is called cohort chart.

pls. check these links:

https://olubukunolaakinsola.medium.com/cohort-analysis-with-power-bi-and-sql-7ebee40a523d

https://www.youtube.com/watch?v=rOJ46AI2gMY 

https://chartexpo.com/blog/cohort-analysis 

https://www.youtube.com/watch?v=vbg4Je1tuis 

https://datapot.vn/huong-dan-xay-dung-cohort-analysis-tren-power-bi/