Convert task to a sub task of a parent / master task?

I have what started out as a Task... with a lot of subtasks, ongoing discussion, etc. and now with that wrapped up and changed to COMPLETED, I need to have it exist as PHASE 1 of a broader project, and create (ideally under a MASTER task that contains Phase 1 and 2) a new PHASE 2 task, with its own subtasks, etc..   Is that possible with Wrike?   Thanks!