You can go to your Contacts screen and click on "All Contacts" or the name of one of your contact lists. You will then have the option to search, filter, edit, move, copy, export and more with your lists and subscribers.
At the top of your list of subscribers, you'll see "tabs" that allow you to see how your contacts are categorized. If you choose one you'll see just that selection, if you choose to highlight more than one tab, you'll see all of those addresses listed.
If you want to export a particular selection or edit a contact, you need to select it or the group by using the check boxes beside each address or to select all addresses, choose the one box at the top beside Email.
Once you've made a selection you can choose from the menu options at the right to take your next action. If you want to export the list, choose "Export".