JSFiddle - React, Tailwind, and code Playground

HTML

<div>
  <button class="decrease" type="button">Обноления поля</button>
  <input type="text" name="field" value="0" />
  <button class="increase" type="button">1</button>
  <button class="increase" type="button">2</button>
  <button class="increase" type="button">5</button>
  <button class="increase" type="button">10</button>
</div>

<div>
тут уже не работает
<input type="text" name="field" value="0" />
тут уже не работает
</div>

JavaScript

Array.prototype.forEach.call(document.querySelectorAll('.increase'), function(v) {
  v.addEventListener('click', inc);
});

function inc() {
  var div = this.parentElement;
  var input = div.children.item(1);
  input.setAttribute('value', (parseInt(input.getAttribute('value')) + 5).toString());
}