JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li><input type="checkbox" name="items[]" value="88712003" id="blah"  /> Parent 1</li>
    <li><input type="checkbox" name="items[]" value="88712003" id="test"  /> Parent 2
        <ul>
            <li><input type="checkbox" name="items[]" value="21312341" id="21312341" /> Child 1</li>
            <li><input type="checkbox" name="items[]" value="21312341" id="21312341" /> Child 2</li>
        </ul>
    </li>
    <li><input type="checkbox" name="items[]" value="88712003" id="sdff"  /> Parent 3</li>
    <li><input type="checkbox" name="items[]" value="88712003" id="fsdff"  /> Parent 4</li>
</ul>

JavaScript

$('ul > li ul li > :checkbox').change(function() {
    $(this).parents('li:last').children("input").attr("disabled", this.checked);
});