HOW CAN I COPY AND PASTE A PORTION OF A TREE
HOW CAN I COPY AND PASTE A PORTION OF A TREE
You don't, - at least not in Geni where the major goal is a world family tree with only one profile per person.
What you do when finding common family is to connect to the existing line instead of copying.
As a starter: Invite one of the manager in the line you want to connect as collaborator if a public profile or a family group member if private profiles.
From the FAQ; Merging: