In monday.com you can add subitems to items. Even though these subitems are viewed in the same board in the user interface, monday.com will actually create and assign these subitems to a separate board. In other words, subitems are managed in a board within a board.
Because of this structure, the backup & restore is also scoped on a subboard.
Snapshots of subitems
The view snapshots of subitems you will need to select the related ‘Subitems of …‘ board.
When you create a copy of subitems, the parent task needs to be present in the board.