How do i cast to level bp

Select the Blueprint in the Main Window (In the Editor, just click on the BP you placed)
Open your LevelBP → rightclick → create Reference.

Here it’s more visible (don’t worry, its a short video)

i have a var and a custom event in my level bp how can i cast to it to get them ?

I think you are asking how to get values form the level blueprint and not how to get properties from an actor from a level blueprint.

If that is true:

You can create Blueprint Level Interfaces and apply them to a sublevel (only sublevels, persistent levels don’t allow it).

https://docs.unrealengine.com/latest/INT/Engine/Blueprints/UserGuide/Types/Interface/UsingInterfaces/#callinginterfacefunctionsonlevelblueprints

Alternatively you can change the way you store information. Instead of keeping it in the level blueprint you could store the data in a manager actor or in the gamemmode/playercontroller/etc.

Lastly, you can call events in a level by using the ConsoleCommand node. Any event on the event graph of a level can be called like it is a console command. So if i make a custom event node in a level called “awesomeEvent” then i can call that just by opening the console (`) and typing awesomeEvent. In the same way you can simulate this using the console event blueprint node. You get no return value though, so no good for getting properties.

i know this video but is from level bp to class bp i need from class bp to level bp

Did you watch the whole video?

yes i have a custom event in the level bp that i want to fire from a class bp

I detail how this works in the answer below

I agree with RimmyD’s answer here, but mainly the part about changing where you have your information stored. Storing things in the Level Blueprint, especially things you need to reference, can cause issues as soon as you start using multiple levels in your project. Please keep in mind that the Level Blueprint is unique to each Level and will change every time the level changes.

Storing these values or creating these events inside of something such as a Game Instance would be much more versatile, seeing as the Game Instance object is created at the beginning of play and is designed to never be destroyed until play has ended. It can also be referenced easily at any time by using the Get Game Instance node.