Actually, M3 motorway is from Lahore to Abdul Hakim. And Abdul Hakim is the junction of M3 and M4 (Faisalabad-Multan Motorway).
M3 ends at Abdul Hakim and M4 continue towards Multan passing though Abdul Hakim.
You can reach Abdul Hakim from Multan through Kacha Khu then have to take motorway for Lahore.
There is "Y" junction on Abdul Hakim where one motorway is for Lahore (M3) and other is for Faisalabad and Islamabad (M4)