JSFiddle - React, Tailwind, and code Playground

HTML

<h3>
<a>Программа на<div></div> c#</a>
</h3>

JavaScript

find("//h3//a[text()=' c#']");
find("//h3//a[.=' c#']");

find("//h3//a[contains(text(),' c#')]");
find("//h3//a[contains(text()[2],' c#')]");
find("//h3//a[contains(string(),' c#')]");



function find(xpath){
var res = document.evaluate(xpath, document, null, XPathResult.ANY_TYPE, null); 
var el = res.iterateNext();
if (el == undefined){
  alert(xpath+" : Not found!")
} else {
  alert(xpath+" : "+el.innerText);
}

}