The Cosco isn't officially compatible with the Bugaboo Bee, but parents have come up with a number of ingenious 'hacks'...
#1. This is using the Bee's Chicco adapter. The Cosco doesn't sit as deep in this frame adapter as it does in others, so if you're going over bumpy terrain you may want to add a luggage strap for security.
#2. This is the most common Bee hack with a luggage strap. The stroller seat is forward facing.
#3. If the Bee seat is rear facing, you can nestle the Cosco between the seat and the handle - here's a photo of the Bee, then a few close-ups and a video of the Chameleon to demonstrate.
#4. And I've left the strangest for last. The Bee's basket is the perfect size and shape to securely wedge the Cosco into it, if the Bee's seat is rear facing. Looks like you're driving a stretch limo, but it works :-).