Blueprint Communication

Im new to unreal
I have a problem with the communication from Hud_Blueprint to Level_Blueprint

I want to have a slider in the Hud which controls the rotation of a cube in the level

In the Hud_Blueprint i have the slider i made in a Widget_Blueprint.
Works perfect printline values from 0 to 1

But since 2 days i have no solution to get the values in the level blueprint.

real quick possible solutions to try:

Thank you

Yes i tried the interface solution, but i make something wrong

And when i implement the members i get no output