Hello! Our Triplanar Sample node is not meant to replace all kinds of triplanar effects, custom solutions would involve setting up your own triplanar mapping solution.
That being said, the link you've shared seems to be broken, can you share it through imgur or a similar service? We might be able to provide some further insight regarding the effect you want to create.
Unfortunately, this can't be achieved through our Triplanar node, you'll have to set up your own custom technique in order to mask the transition between the textures.
I can recommend that you look into our Triplanar sample as a reference, and perhaps even the Substance sample in order to see how you can achieve height blending.