Version: v4.x
View bounds

Usage
Click a rectangle to fit the map to its bounds
Live Editor
const innerBounds = [
  [49.505, -2.09],
  [53.505, 2.09],
]
const outerBounds = [
  [50.505, -29.09],
  [52.505, 29.09],
]

const redColor = { color: 'red' }
const whiteColor = { color: 'white' }

function SetBoundsRectangles() {
  const [bounds, setBounds] = useState(outerBounds)
  const map = useMap()

  const innerHandlers = useMemo(
    () => ({
      click() {
        setBounds(innerBounds)
        map.fitBounds(innerBounds)
      },
    }),
    [map],
  )
  const outerHandlers = useMemo(
    () => ({
      click() {
        setBounds(outerBounds)
        map.fitBounds(outerBounds)
      },
    }),
    [map],
  )

  return (
    <>
      <Rectangle
        bounds={outerBounds}
        eventHandlers={outerHandlers}
        pathOptions={bounds === outerBounds ? redColor : whiteColor}
      />
      <Rectangle
        bounds={innerBounds}
        eventHandlers={innerHandlers}
        pathOptions={bounds === innerBounds ? redColor : whiteColor}
      />
    </>
  )
}

render(
  <MapContainer bounds={outerBounds} scrollWheelZoom={false}>
    <TileLayer
      attribution='&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors'
      url="https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png"
    />
    <SetBoundsRectangles />
  </MapContainer>,
)
Result