List of multi-levels per dataset.

Obtain list of all multi-levels associated with particular datasets.

Some datasets might live alone without any levels associated with them.

Reservations (Dataset)
│
└───Room Reservation (Multi-level)
    │
    └─── Room Check-in (CDF)
    │
    └─── Room Check-out (CDF)
    │
    └─── Room Reservation Status (CDF)