If you want to access the same files as other users in your lab, do not try to share a single local database. The best solution is to set up a Shared Database. This is an SQL database installed on your own in-house server that integrates seamlessly with Geneious via the Shared Databases icon in the local database. Users can drag and drop files from their local database into the Shared Database to share with colleagues, and each user's access to individual folders within the database can be controlled by the server administrator.
See chapter 20 of the Geneious user manual for further details.