The Boyle's law belongs in the region marked X whereas the other circle belongs to Charles law. There is inverse relationship between the two circles or these two laws because in Boyle's law, temperature is constant while on the other hand, in Charles law pressure is constant instead of temperature. In Boyle's law, pressure of a gas is inversely with its volume whereas in Charles law, the volume of a gas is directly proportional to its absolute (Kelvin) temperature.
