JSFiddle - React, Tailwind, and code Playground

HTML

<select id="company">
    <option selected="true" >ALL</option>
    <option>GM</option>
    <option>Honda</option>
    <option>Ford</option>
    <option>TEST</option>
</select>
<select id="names" multiple="multiple" size="8">
    <option>Chevy GM</option>
    <option>Buick [GM]</option>
    <option>Civic [Honda]</option>
    <option>Accord [Honda]</option>
    <option>Focus [Ford]</option>
</select>
<div id="testing">
  <p>
  testing [TEST]
  </p>
</div>

JavaScript

$(function() {
    $("#company").change(function() {
        var val = $(this).val();
        $("#names option").hide().filter(function() {
            var regExp = new RegExp("\\[" + val + "\\]$");
            return (val == "ALL") || regExp.test($(this).text());
        }).show();
    });
});