Get rest of the string from known place
JavaScript
var str1 = '/slm/campaigns/new';
var str2 = '/slm/campaigns/edit/30';
var str3 = str1.substring(str1.indexOf('/campaigns/'));
var str4 = str2.substring(str2.indexOf('/campaigns/'));
console.log(str3);
console.log(str4);
// will output string after AND including /campaigns/