JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="search">
<ul id="myMenu">
    <li>test</li>
    <li>foo</li>
    <li>bar</li>
    <li>hello</li>
    <li>
        <ul>
            <li>john</li>
            <li>smith</li>
            <li>hello</li>
            <li>world</li>
            <li>bar</li>
        </ul>
    </li>
    <li>one</li>
    <li>two</li>
    <li>three</li>
</ul>

JavaScript

$( function() {
    $( '#search' ).keyup( function() {
        var matches = $( 'ul#myMenu' ).find( 'li:contains('+ $( this ).val() +') ' );
        $( 'li', 'ul#myMenu' ).not( matches ).slideUp();
        matches.slideDown();    
    });
});