List administrators can export their list's subscribers in 2 ways. In both cases the first step is to set the member addresses to 'No'.
Go to: Admin > Privacy options. Scroll to the bottom of the page to:
Show member addresses so they're not directly recognizable as email addresses? NO
Login to your list's administration page and in the browser address bar, replace 'admin' with 'roster'. For example:
https://lists.mydomain.com/mailman/admin/mylist
=>
https://lists.mydomain.com/mailman/roster/mylist
This will display your subscribers addresses for regular and digest delivery.
Send an empty email to your list's request service. For example:
To: mylist-request@lists.mydomain.com
Subject: who ADMINPASSWORD
Replace 'ADMINPASSWORD' with your actual administrator password.