WorldCat Local uses the WorldCat database for discovery. As long as your holdings are set and up-to-date in WorldCat, users will find your library's resources. When each library is identified in the local catalogue as holding the item, then sharing of bibliographic records is not an issue.
WorldCat Local can be configured to display holdings of a group of libraries—even those that do not share a union catalogue—in search results. The libraries in the group can determine how to best link users to their resource sharing option.