If you want to prevent designs or objects from being selectable in the Main View, you can ‘Lock’ them. Locking an object does not affect its grouping; it only prevents it from being clicked on. The second button, a white lock with an ‘X’ on it, will not only lock the design or object, but will prevent it from being displayed in the Main View.
To unlock something, click the third lock, which appears as an open lock icon.
Note: Locking does not prevent you from selecting it in the Object tree, where it can be resequenced, copied, or deleted.