JSFiddle - React, Tailwind, and code Playground

HTML

<input type="hidden" name="URL" id="URL" value=" http://www.example.com/edit-your-profile/#file%5B0%5D%5Bstatus%5D=Complete&file%5B0%5D%5BremoteFileURL%5D=http%3A%2F%2Fi.imgur.com%2Fe0XJI.jpg&file%5B0%5D%5BfileSource%5D=Previous%20Uploads&file%5B0%5D%5BpicID%5D=p43" />

JavaScript

var url = document.getElementById('URL').value;
var myRegexp = /(?:file%5B0%5D%5BremoteFileURL%5D|remoteFileURL)=(.+?)\&/;
var match = myRegexp.exec(url);
alert(match[1]);