Bring 1 inch of water to a boil in a large saucepan. Put green beans in a steamer basket, place in the pan, cover and steam until tender-crisp, 4 to 6 minutes.
Meanwhile, heat oil in a large skillet over medium-high heat. Add garlic and paprika and cook, stirring constantly, until just fragrant but not browned, about 20 seconds. Add shrimp and cook until pink and opaque, about 2 minutes per side. Stir in butter beans (or cannellini) and vinegar; cook, stirring occasionally, until heated through, about 2 minutes. Stir in 1/4 cup parsley.
Divide the green beans among 4 plates. Top with the shrimp mixture. Sprinkle with pepper and the remaining 1/4 cup parsley.