You can access database connections assigned directly to you or database connections assigned to a group to which you belong.
When documents are assigned to a group, the database connections that the document uses must also be assigned to the group. Otherwise, group members can access the document, but they cannot access its data values (unless they have individual user access).
To mitigate the risk of conflicting permissions, store documents with the database connections they reference. Whenever possible, distribute documents and database connections to groups. It is easier to set permissions for all files in a folder, and all users in a group than it is to manage permissions for individual files and individual users.