A single workspace — along with whichever of its repositories, Domains, and Agents you choose to bring along — can move from your own context into someone else's, right from that workspace's row menu.
Anything you choose to carry over is added to the destination if it doesn't already have it, and reused if it does, rather than duplicated. Anything you leave unchecked is simply dropped from the moved workspace instead of pointing at something that no longer exists.
This moves the workspace, not copies it — once it's moved, it's gone from where it was and living in the destination context instead, worktree and all.