Click Subscribers on the left menu.
Select the List the Subscriber(s) are in.
Select the Subscribers you want to move/copy, then click either Move or Copy.
Move - removes them from the current List and puts them in a new List.
Copy - keeps them in the current List and add them to a new List.
If you want to see which List(s) a Subscriber is in just click the 3 dots on the far right, then click Edit.
You can also view and change which List(s) they are contained in from here.
You cannot manually add people to a Planning Center List from within Clearstream. If you want to add someone to a Planning Center List, you'll need to do that from within your Planning Center account. That being said, you can push new Clearstream Subscribers into Planning Center.