Yes. The Comfort Transport Bag fits Donkey 5 Mono, Duo and Twin. Both the chassis and the seat unit(s) fit inside.
Packing tips:
Fold the chassis completely; remove wheels if needed.
Place the seat unit(s) on top and use the internal straps to keep everything snug.
Keep small parts (adapters, cup holder) in a zip pocket/pouch.
Video guide: https://youtu.be/gwK26m8rUJc?si=-hvyrr027zrGY9n6
That's the list of strollers that fit into the bag:
Bugaboo Ant
Bugaboo Bee (2007 model)
Bugaboo Bee (2010 model)
Bugaboo Bee 3
Bugaboo Bee 5
Bugaboo Bee 6
Bugaboo Buffalo
Bugaboo Cameleon (2007 model)
Bugaboo Cameleon 3
Bugaboo Cameleon 3 plus
Bugaboo Donkey
Bugaboo Donkey 2
Bugaboo Donkey 3
Bugaboo Donkey 5
Bugaboo Dragonfly
Bugaboo Fox
Bugaboo Fox 2
Bugaboo Fox 3
Bugaboo Fox 5
Bugaboo Fox Cub
Bugaboo Lynx
Bugaboo Kangaroo
Bugaboo Fox 5 Renew