The way I do it is to put it into a "group" that you can allow the other groups to see.
If it's for ProjectA but for instance ProjectB and ProjectC users need to see it but can't see anything else in A, then it has to be in something like ProjectD that all groups can see. Then you can map it various places using Saved Searches or Smart Folders.
Often I end up with ProjectA-edit, ProjectA-approval and ProjectA-raw groups that serve the same project but that way you can hide clips from different groups of users. The editors could see edit, approval and raw, the producers might only see approval, for instance.
It becomes a balance of groups, users, catalogs and names that you work with to create your workflow.
This is one of those areas where "knowing" CatDV is different from creating a working solution. The layout and intended use of media seriously impacts the way you build the database and user structure. Go slow and remember, you can always change it up later.
Thank you for your response.
Its quite something to get your head around....:)
If I do like you suggest - and don't want to end up with one big smart folder but want in a way to have the same structure as I have in all the catalogs I have put in e.g.. Project D. What will the best way of doing that. Without having to make new smart folders each time I bring in a new catalog - but something more dynamic and without ending up with one big smart folder trying to contain all my clips ind "Project D".