JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.8.13/jquery-ui.min.js"></script>
<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.13/themes/base/jquery-ui.css">
<input id="ac" /> <span>choose: Multiple item with similar words</span>

JavaScript

var validOptions = ["Item 1", "Item        1", "Item     1", "Item 2", "Item   2"]
previousValue = "";

$('#ac').autocomplete({
    autoFocus: true,
    source: validOptions,
}).keyup(function() {
    var isValid = false;
    for (i in validOptions) {
        if (validOptions[i].toLowerCase().match(this.value.toLowerCase())) {
            isValid = true;
        }
    }
    if (!isValid) {
        this.value = previousValue
    } else {
        previousValue = this.value;
    }
});