Changint parameter for dynamic material instances

After creating a dynamic material instance I try to change the parameter of the parent of this instance for the dynamic material instance but it doesn’t work. When I change the material itself all my actors with this material get this parameter changed but I only what to get one actor changing it’s parameter and so it’s appearance. Thanks

Here’s a picture. I tried it with two nodes but it didn’t work.

Without a parameter collection it works.