If you found your rewrite module not working well even mod rewrite is enabled, try to do the following change:

Search AllowOverride None from httpd.conf and replace it by AllowOverride All.

Restart your service and check your page again, the rewrite rule should be working now.

Share a rewrite format that you can rewrite a sub domain to a sub directory ( not redirect ):

For example:
http://hello.cambyliverson.com
You will see the content of /hello
Which the url keep showing as http://hello.cambyliverson.com
Below is the code

RewriteCond %{HTTP_HOST}   ^[www\\.]*sub-domain-name.domain-name.com [NC]
RewriteCond %{REQUEST_URI} !^/sub-domain-directory/.*
RewriteRule   ^(.*)  /sub-domain-directory/$1  [L]