You can get that same functionality as long as each user has their own Realm. Permissions on a Full Sync Realm can be offered to other users to allow them read/write access to a users Realm.
See Offering Permissions
You would need to break down your global realm into individual ones but that's one option.
If you are storing all users data on one, global realm. It’s going to be a bit more challenging as you don’t have a fine grained control over what other users are doing.
However, you could implement logic in the app that controls who can/cannot work with an object. So for example, a ToDo object could have a ‘created_by_user_id’ property
class ToDoClass: Object {
@obc dynamic var to_do_id = ""
@obc dynamic var created_by_uid = ""
override static func primaryKey() -> String? {
return "to_do_id"
}
}
and using app logic, when another user goes to delete that users ToDo, it could compare the created_by_uid property to the current users id to see if they match. If not, disallow delete.