Original Question: https://wordpress.stackexchange.com/questions/283420/
There are three files in order to make this work:
- filter.php - The HTML that is required for the markup to work.
- custom.js - The javascript that uses Ajax calls to get the necessary data.
- functions.php - the functions you will place inside your functions.php
Video walkthrough: https://youtu.be/-WyScMmjENo