How to make a universal address?

Question

htaccess

Honestly, I tried, I don’t understand how to unify this line, I want to get something like instead of site.ru, but as soon as I didn’t try, it doesn’t work
RewriteCond %{HTTP_HOST} ^sub\.site\.ru$ [NC]
https://sub.%{SERVER_NAME}%{REQUEST_URI}

Answer 1

RewriteCond %{HTTP_HOST} ^sub\. [NC]
but "subdomains of subdomains" will also satisfy it. or but this is if the “root domain” is the second level ( ), and not the third, for example.
{2}