JSFiddle - React, Tailwind, and code Playground

HTML

<div id='buscaraqui'>

<div>        <div>        <div>
   Diego       Ademir      Diego
   Maicon      Diego       Maicon
   Adriana     Maicon      Ademir
   Magda       Adriana     Adriana
   Delvair     Magda       Ademir
   Roselene    Delvair     Delvair
   Lawiny      Ademir      Lawiny
   Nicolas     Lawiny      Roselene
   Alice       Nicolas     Nicolas
   Ademir      Alice       Alice
   Júlia       Júlia       Ademir
</div>       </div>       </div>

</div>

JavaScript

var str = document.getElementById("buscaraqui").innerText;

var count = (str.match(/Ademir/g) || []).length;

alert(count)