I'm attempting to allow users to access the same multisite content on a sub-site by using both www.example as well as www.example.

Upon initial setup, I simply redirected all allowed hosts / server aliases (e.g. www.example) to the Server Name entry (e.g. www.example). This worked fine for the last few months.

However, I was recently approached by the client who is requesting the requested domain remain in the browser's address bar (a simple redirect from an Apache no longer fulfills client requirements). They are in the non-profit sector and the extension is important to them.

With single-site setups, I'd usually use update_option('siteUrl', $_SERVER['SERVER_NAME']) to achieve this functionality. However, with a multisite, my research suggests that those hooks do not work the same way.

What is the secret to doing this? I find it hard to believe we can't have a similar functionality in the multisite world.