ARKit – Apply CIFilter to a specific vertices of ARFaceAnchor

I'm trying to apply a CIFilter to a specific group of vertices from the ARFaceAnchor. I was able to access the vertices using:

let vertices = faceAnchor.geometry.vertices 

let relevantVertices = [vertices[580], 
                        vertices[1019], 
                        vertices[1017], 
                        vertices[660]]

But I can't understand how to use it in with a node (not sure if that's the solution) in order to keep those vertexes continuously updated with the CIFilter as the face moves.

For example, I chose some vertexes and applied a black and white filter on the selected vertices (hard-coded) using Photoshop for demonstration. Imagine there are no lines :)

Any help would be highly appreciated!

from ARKit – Apply CIFilter to a specific vertices of ARFaceAnchor