This feature is accessible by users with Manager level or higher permissions. Take a look at this article to learn more about the different access levels for a MailChimp account.
The unique list ID for each list in your account can be seen on the Lists page when you click on the Gear drop down.
If you need to copy the ID to use for a plugin or integration you can do that by navigating to the Lists page, clicking the Gear drop down and selecting List Settings and Unique ID.
The unique ID for that list is located at the bottom of the page