Multiple Subscription pages

I run 3 websites on the same server account and have 1 phpList installation as a directory under public_html. I don’t want to do 2 more installs.

What I want to do is 3 separate front end and subscribe pages for each list. But I cannot find discussion on how to do this. I do not want people to see all three lists but rather one list per website.

Can someone tell me or point me in the right direction.