I want to display the altitude of the craft on my HUD. or an altitude meter

Sorry to bother you again Everynone
I have replicated everything in your example widget BP but just cant get the altimeter MID node to the set brush to material node like you have .
What is the Altimeter MID?
Everything I Tried after dynamic material instance to get to the set brush node, does not want to connect .
What did I miss?
Thanks