Animate a mesh inside a blueprint

Hey there,

with my little knowledge, I was able to animate a mesh in the persistent level with a Matinee scene. I selected the Mesh and created a new skeletal group where I added my from blender exported animation.

Now I want to do the same with the same mesh inside of a blueprint instead of the persistent level. Selecting it in the viewport to create a skeletal group in the Matinee editor does not work.

Looking forward answers!