const regex = /(?m)(^.*\/).*/g;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('(?m)(^.*\\\/).*', 'g')
const str = `http://xxxx.com/xxx-xxx-xxx-xxxx/ 60% 2 Weekly 2014-01-01 00:00
http://somethingelse.com/123-456-789-0000/ 60% 2 Weekly 2014-01-01 00:00
http://anothersite.com/page/boop/beep/ 60% 2 Weekly 2014-01-01 00:00
http://baloogawhalesarenotaliens.com/ 60% 2 Weekly 2014-01-01 00:00
`;
const subst = `$1`;
// The substituted value will be contained in the result variable
const result = str.replace(regex, subst);
console.log('Substitution result: ', result);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions