Jezeb can be found either straight at the entrance of Leoric's Manor, or further inside up the left staircase.

Try to get at least 15 kills before ascending to the Leoric's Hunting Grounds. You need to kill the mages around him first.

Cadul can be found on the pedestal in the center of the map. This kill bounty doesn't have a quest marker. This way is superior, but it's way harder to explain and people need to pay attention for this to work. Finally, the 3rd player is doing their boss as their 3rd quest. Another player goes second, and they are doing first some other quest and then the boss. The player running Act 2 is always starting the game with his boss bounty. This is very easy to organize, but if your game has Belial, Diablo and Malthael at the same time, your boss killer won't be able to kill all bosses before all other bounties are done. Have 1 player do all 4 (or 5) boss bounties, while other 3 players ignore those quests completely. Only one bossfight can be active at a time, meaning that when you reach the boss door and one of your teammates is currently fighting another boss, you will be unable to enter. The tricky part comes when you consider the group play. This bounty type is even more straightforward: you run to the boss, you kill the boss.

Diablo iii act iv dialogue