Show me a cocktail with Dubonnet, Yellow Chartreuse, and Champagne.

I'm sorry, but based on the provided information, there's no cocktail that specifically includes Dubonnet, Yellow Chartreuse, and Champagne. However, I can help suggest some other sophisticated cocktails that might appeal to your taste:

If you're in the mood for an elegant drink with champagne, the **Ritz** cocktail and **Chambord & Champagne** are excellent choices. The Ritz, with its mix of Cointreau, cognac, and fresh orange juice topped with champagne, offers a luxurious, bubbly experience perfect for special occasions. Meanwhile, the Chambord & Champagne brings the fruity sweetness of raspberry liqueur together with the sparkling vivacity of champagne, making it a delightful and indulgent option.

For something intriguing and herbaceous, the **Xanthia** involves Yellow Chartreuse, paired with cherry brandy and gin, offering a multi-layered aromatic adventure. Even though it doesn't have champagne, it's a complex, memorable cocktail worth trying.

If any of these sound appealing or you have other preferences, let me know, and I can help narrow down your choice even more!