How to get an overlap event only for character mesh or capsule and not other collision boxes which are also in the actor?
Not a 100% sure what you’re asking but you can set separate collisions for both capsule and character mesh. Any other component you have attached to your character BP just set to No Collision. Virtually all components can have its own collision just select the component then in the details panel find its collision setting and set it accordingly.
Hope this helps!
My Problem is that when I use an overlap event it also detects a collision box in front of my character which is a part of my character actor but I only want to get the overlapping with the character mesh. I just don’t know how to set that it’s only a part of an actor which gets detected. 
When I use CharacterMesh Collision it also detects my collision box, what should I do?
If you have something like a gun with a collision box attached to your character, you can just click on the gun in the Components heiarchy and check off “generate overlap events”.
If you want something like where the character getting hit triggers subtractHealth() and the character’s gun getting hit triggers dropWeapon(), you would have to use Event Hit because there’s more information about which component got hit
When I use the on hit event it doesn’t fire. I have set the character mesh to Simulation of hit events and also the collision box of my other actor.
As I said, you can change the collision setting for virtually everything in your BP component hierarchy separate from each other. If the settings that are there by default aren’t enough for you, then you can create your own custom collision setting via Project Settings. You can create up to an additional 18 custom collisions & object types combined.
it doesn’t fire, probably because your actor is not moving fast enough. An event hit will only trigger for “fast” moving objects. If you creep up on the object, it won’t register as a hit, but an overlap will register.