I'm trying to setup a nginx server which dynamically loads content from a folder for a domain. To do this I'm using regular expressions in the server name like so:

server_name ((?<subdomain>.+)\.)?(?<domain>.+)\.(?<tld>.*);

This will create a 3 variables for nginx to use later on, for example when using the following url: test.foo.example.com this will evaluate to:

1. $subdomain = test.foo
2. $domain = example
3. $tld = com

The problem arises when the co.uk top-level domain is used. In this case when using the url test.foo.example.co.ukit will evaluate to:

1. $subdomain = test.foo.cedira
2. $domain = co
3. $tld = uk

How can I edit the regular expression so that it will also work for co.uk?