JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/rxjs/6.3.3/rxjs.umd.js" type="text/javascript"></script>
<div class="container container-1">
  <input type="radio" name="group-1" value="1" id="">
  <input type="radio" name="group-1" value="2" id="">
  <input type="radio" name="group-1" value="3" id="">
</div>
<div class="container container-2">
  <input type="radio" name="group-2" value="4" id="">
  <input type="radio" name="group-2" value="5" id="">
  <input type="radio" name="group-2" value="6" id="">
</div>
<div class="container container-3">
  <input type="radio" name="group-3" value="7" id="">
  <input type="radio" name="group-3" value="8" id="">
  <input type="radio" name="group-3" value="9" id="">
</div>
<button id="button" disabled>Click</button>

JavaScript

const { from, fromEvent } = rxjs;
const { mergeMap, first } = rxjs.operators;

const query = document.querySelectorAll(".container");
const applyButton = {complete: () => document.querySelector("#button").removeAttribute("disabled")}

from(query)
.pipe(mergeMap(v => fromEvent(v, "input").pipe(first())))
.subscribe(applyButton);