BetterEnd/json/block/%name%_brick_half_slab.json

{
    "parent": "block/slab", 
    "textures": {
        "bottom": "betterend:block/%name%_bricks", 
        "side": "betterend:block/%name%_bricks", 
        "top": "betterend:block/%name%_bricks"
    }
}