Destroy all enemy actors when level cleared

Hello, unreal community, my current objective was in order to clear a level, the player has to kill a certain number of monsters. Once achieved then destroy all types of monsters and dismantle any traps to show that the level is cleared.

In this picture below is the tracker on how many monsters to be killed in order to go to the next level.

However, I am yet still figuring out how do I destroy multiple actors of a single category.

Your comments will be of great help to me.