“orderby=nicename” How can we make this happen?

I want to sort categories by nicename, or slug. I went through some files hoping I’d find an easy place where the options for orderby were listed and where I could add a bit to pull the nicename values but I can’t find it.

Anyone up to this task? Is it possible?

The reason I ask is because my former method is no longer working with upgrade, as you can see here: https://tinyurl.com/ynjhgu

The invisible bits I added to create last name alpha order are now visible and I can’t get them to go away.