How can I control multiple post process effects in blueprint?

Hey all,

I recently started using unreal and have come to a point where I want to make level building easier from a design point; Using blueprint and construction Scripts.

I saw the video tutorial on how to set up a WallSconce, and would like to do something similar with post process effects. Basically, I want to control my two post process effects using blueprint construction scripts.
I think I am suppose to the use “add or Update Blendable” function somehow, but I cannot for the life of me figure it out.

Any help out there?
Thanks.