Melt butter in a 4-quart Dutch oven over medium heat. Add onion, bell pepper, green onion, and garlic. Cook, stirring occasionally, until vegetables are tender, 8 to 10 minutes.
Stir in the flour. Cook for 1 minute. Add broth. Cook and stir until bubbly. Add beer and cream. Stir in corn and potatoes. Bring to a boil. Reduce heat and simmer, uncovered, 5 minutes, stirring occasionally.
Gradually add sharp and white Cheddar cheeses, stirring after each addition until the cheeses are melted. Stir in bacon, Parmesan, and hot pepper sauce. Heat through. Remove from heat and let stand for 10 minutes. Top with additional green onion and bacon. Serve.