Comment 1 for bug 1517712

This already exists. Go to your user options page for any list in the installation for which you are subscribed at a URL something like http://www.example.com/mailman/options/LISTNAME. Log in with your subscribed email address and list password. If you don't know your password, get an immediate email reminder by entering your email address on the login page and clicking the Remind button.

Once logged in, click the "List my other subscriptions" button to get a list of all the lists in the installation to which your address is subscribed.

Is there some reason why this is insufficient for your request?