How to learn about Table Manipulation for set membership

Hi All,
I just heard @BrianJulius talk about the power of using table manipulation functions for the analysis of membership in sets over time. He mentioned its applicability to business analytic challenges such as customer churn, employee attrition and more.

I’m intrigued! I’d love to take some training and/or see examples of the analysis of “membership in sets over time,” especially applied to trouble tickets and inventory. I’d be interested in the appropriate data shaping in Power Query and table functions being applied to that type of analysis.

Could you direct me to where I could find that? (Googling and asking ChatGPT didn’t help).

Julie