Remove Z values of Coordinate List based on Another Coordinate List

So just to try to clean up the thread in case anyone comes across it in the future, this is what I ended up doing to solve my original problem:

I grouped all of my points based on their X and then by their Y, using a variation of the information found here:

Since my intersection point always came in at the last index (index 5), I ran a comparison operation on all of the Z coordinates as compared to the Z coordinate of the last item of each sublist. as shown below.

I then thought I could then use a “BoundingBox.IsEmpty” or “BoundingBox.Contains” to figure out which Revit Elements contained these points, therefore these would be the ones that were to get the parameter modification. However both nodes return false no matter what I try. I even tried adding a “Sphere.ByCenterPointRadius” thinking maybe a point wouldnt trip the “BoundingBox.IsEmpty” node, however even that isn’t working.