How to fire only on a child element?

Question

css

Subject, how to make that, when clicking on the same classes, the function would work only for the first child and that's it, and not for the entire branch https://jsfiddle.net/m0z59dxa/6/

Answer 1

https://jsfiddle.net/m0z59dxa/21/
https://jsfiddle.net/m0z59dxa/25/