How to make unlimted placeholders

Hey guys
I have seen some templates on VH which shows that there are unlimited placeholders .
I would want to know how to do that , do I need to make a Video Tutorial in the File and direct users to use script " True Comp Duplicator " .

You make a separate project where there’s just one comp (the one you want to be duplicated unlimited number of times).

Now the user can import this project, into a NEW project, and drag the comp in the timeline. And you can repeat this process as many times as you want. The same way you import images,videos, etc, you can also import other after effects project files.