How to know Subdomain list from webshell and how to filter domain

Hey do you have seen webshells and have a lot of domain list?

Example:

Yes its a domain but it can be subdomain too, if you dont believe it u can see on folder /home/$user/access-logs/, and u can see subdomain list on that website, and then u just mass deface :D 

but wait, you already mass deface it but you want copy that subdomain list manual? hell nah i will tell you how to filter that domain ok lets go

1.Open website http://domaincheckplugin.com/extractor
2. Drag + Copy all of them on access-logs, like this :

3. paste on http://domaincheckplugin.com/extractor 

    example:

4.and then click find domain

5.You can see a result

Hope u enjoy

see ya