Thanks for filing this inquiry into the URL change. I presume this is for your Jive environment. This is primarily determined by the jiveURL system property, which is found in the Jive Admin Console under System > Management > System Properties. This must be followed by a restart. If you have multiple application nodes in a clustered environment, you'll need to restart all the nodes at the same time.
In addition, please also refer Considerations when changing the jiveURL for additional details on other impact this may have on your site.
Let me know if you have any other questions on this.