I'll create a nested modal component that demonstrates a modal within a modal within a modal using shadcn/ui components.

This implementation creates three nested modals:

1. The first modal opens when you click the "Open First Modal" button
2. Inside the first modal, you can click "Open Second Modal" to open a second modal on top
3. Inside the second modal, you can click "Open Third Modal" to open a third modal on top

Each modal has:

• Its own state management using React useState hooks
• Different sizes to create a visual hierarchy
• Proper focus management (handled by the shadcn/ui Dialog component)
• Proper accessibility attributes

When you close a parent modal, all child modals will also close automatically. The escape key will close only the top-most modal, allowing you to navigate back through the modal hierarchy.