Ability for users to manage which list they belong to

Hello @BMHS1967 ,

You can add a coded sign up form to a webpage, which would allow contacts to sign up for and manage their subscriptions to a degree. However, the main way of contacts seeing their list memberships and managing them is through the Update Profile form that's only available via the footer of emails, or as direct emails to send to contacts.

For additional info and voicing what you're wanting in regards to the Update Profile system, I'd recommend voting and posting in this feedback thread.