As of iOS 14,
NSPersistentCloudKitContainer only supports the private database and the public database. If you want your users to be able to share data with others, you need to implement that code manually.
Here's a great explanation of how sharing works along with some sample code:
https://developer.apple.com/documentation/cloudkit/sharing_cloudkit_data_with_other_icloud_usersIf you want to share a certain object, you can ask
NSPersistentCloudKitContainer for the underlying record using
https://developer.apple.com/documentation/coredata/nspersistentcloudkitcontainer/3141668-record. Initialize a new
CKShare and set the record as its root record. Retrieve all other records for the hierarchy you'd like to share and set their
parent property to the root record (not the share). Then you can save the
CKShare using
CKModifyRecordsOperation. Please refer to the documentation I've mentioned above to set up a
CKDatabaseSubscription and fetch changes from the shared database as. they come in.
