Repetir os resultados com base na categoria, mas mostrar a categoria apenas uma vez

$currentProduct = null;

foreach($products as $product) {

    if ($currentProduct != $product['product']) {
        // We got a new product. Show it with some fancy html
        // Then store it in $currentProduct for the next iteration 
        $currentProduct = $product['product'];
    }

    // Show the title with some fancy html
}