We don't currently have a way to do this in Clubhouse, but you can use our API to move Stories between Workspaces (it may require some developer resources from your team).
First, you'll need to export your data from the first Workspace. You can do this using our exporter. Once you have all of the data exported, you will need to work with the parent data from the Stories you wish to move (associated projects, epics, workflows, etc.) and update and re-map the object IDs to match the new Workspace.