Yes you can do it but its a bit involved. for simple materials where the 2nd ground is 100% flat you can simply lerp to an un-transformed world normal (must have tangent space normal = FALSE in material settings), and then lerp to a transformed tangent-> world normal for the rest.
if you actually want it to match the normals of another terrain then you will need to store that terrain normal and build a transform basis for it. It is doable but I am about to run out so can’t post much more detail atm.