This is a Simple dropdown list using which you can show checkboxes with Select Options. During run-time after select the required values it will show all those values with Count in Select box.
The Control is so simple by just Copy Paste you can implement this in your App. The html file I created for demo is with 2 files referred. 1 js and 1 css file. JS file contains Scripts and CSS file contains the look and feel. You can change the Style as per your need.
Developed by https://jharaphula.com/data-json-to-html-table-php/