You may create ("embed") a shared workspace inside a workspace using  File    Access    Invite Member   or using  Public Access   from the folder's action menu. You may transfer a workspace into another one (cut and paste).

The the members of the higher-level workspace (its BSCW group) are automatically added to -- or removed from -- the members of the embedded workspace (its BSCW group): embedding a workspace in another one, or removing a workspace from another one, automatically changes the membership of the workspace that you transfer. Remember to check whether these automatic changes are what you intented and correct the membership (see 4.5) and the access rights (see 4.7), if necessary.