If two resistors (5 Ohms & 10 Ohms) are connected in parallel, current will flow through both resistors. Then, assume a parallel circuit (5 Ohms & 0 Ohms), why does current flows to the path with 0 Ohms only and not through both of the paths?
Because an ideal 0 Ohm resistance would offer no resistance to flow, while the 5 Ohm line would offer resistance. Energy travels from high to low potential through the path with the least resistance.
Assuming the resistance isn't a function of current for the 0 Ohm line (not realistic usually; but for a theoretical ideal situation it's what we're concerned about), there's no reason for the current to flow through the line with resistance. You have a path with no resistance, and infinite capacity; which is why all the energy wants to choose that path.
The reason it might not make sense intuitively is because in real situations, this doesn't really happen. With two non-superconducting wires, one having a 5 Ohm resistor and one having no resistor, there should still be some current through the 5 Ohm resistor. This is because regular wire has an internal resistance, and so all the energy cannot freely flow through as it would with an ideal 0 resistance path.