JSFiddle - React, Tailwind, and code Playground

HTML

<span> hello this is test <span onclick="showParentText(this)">click here</span></span>

JavaScript

window.showParentText = function(obj) {
    var thisText = obj.outerHTML,
        parentText = obj.parentNode.innerHTML;
    
    alert(parentText.replace(thisText, ""));
}