How to render a block with faces like a grass block?

[fluid bluff]

Right now I'm currently trying to get nether bricks to be using multiple textures, randomized in weights and it worked, however, I also wanted to see if I could try to get it to recognize a texture to be the "top" of the block whilst the rest are the textures are being used. As of right now, I somehow managed to make the block invisible rather than it being the 404 texture, anyone know how to fix it? This is what I have set for the textures.

[fallow magnet]

parent block/block only contain display settings.

block/cube_top will have top and side texture.

[fluid bluff]

ahhhh, gotcha

lemme try that

yup that worked!