Blueprints - Set Material on Actor Via Widget


So I’m complexity lost in my blueprints and really need some help. So i’ve set up a UMG widget that spawns etc. just fine. In it are 4 buttons, just named “1,2,3 and 4”. What these need to do is to simply change the material on a actor.

I can’t for the life of me get them to actually edit the actor. I know the buttons are working fine as i’ve used print strings to tell me when its failed. And i’m 100% sure its because they can’t ever see the actor. Is their a specific way i’m supposed to be bringing that actor into the UMG widget so that it can see it and edit it?

The code is in such a mess right now that screengrabs aren’t even worth it. Has anyone in the past got something similar to work and can point me towards it?