How to display a list of child elements when clicking on an element?

Question

WordPress

Good day, there is a list of parent elements in the form of a table:

How, when you click on the "OPOR" button, display child elements, like this:

The difficulty is that there can be many parent elements (more than 9), so it makes sense to give ID everyone is not.
In fact, you need to get an array of these buttons and when you click on the button, display a block with children, but how to fix the array clicks? tell me the algorithm please.

Answer 1

Try get_term_link instead of get_permalink

Answer 2

For example, like this: https://jsfiddle.net/n5xxm3h5/