JSFiddle - React, Tailwind, and code Playground

HTML

<select id="ComboBox">
    <option value="0">Value 0</option>
    <option value="1">Value 1</option>
    <option value="2">Value 2</option>
    <option value="3">Value 3</option> 
</select>

<select id="ComboBox2">
    <option value="0">Value 0</option>
    <option value="1">Value 1</option>
    <option value="2">Value 2</option>
    <option value="3">Value 3</option> 
</select>

<div id="total"></div>

JavaScript

$(function() {
    $("select[id*='ComboBox']").change(function() {
        $("#total").text($("select[id*='ComboBox'][value!=0]").length);
    });
});