Hi Martina,

You can add composite products to a group by adding the custom code below. (How to add custom code? ↗):

add_filter( 'woosg_product_types', function ( $types ) {
    unset( $types['composite'] );
    unset( $types['wooco'] );
    return $types;
} );

However, you can't add a grouped product to the composite. Each component product in a composite must be purchasable so that the buyer can choose.

I've updated the snippet, and it works fine now: https://inbusta.altervista.org/prodotto/menu-benessere-prova/

However, composite products are required to have selected component products before being added to the cart. So, it would be best if you didn't show the add-to-cart button on the grouped products:

Please recheck it https://inbusta.altervista.org/prodotto/menu-benessere-prova/

-----

Updated snippet:

add_filter( 'woosg_product_types', function ( $types ) {
    return array_diff( $types, [ 'composite', 'wooco' ] );
} );

Adding a variable product to a group will show an attributes selector like that (https://demo.wpclever.net/woosg/product/smart-grouped-product-01/). However, we can't implement the same behavior for composite products. A composite has a products selector—not an attributes selector.

Our plugins do not support combining grouped and composite product types. We can only display selected composite products in a group so buyers can open and buy them individually. You can also use the WPC Smart Quick View (https://wordpress.org/plugins/woo-smart-quick-view/), and buyers can open these composite products in a quick view popup without being redirected to another page.

Please add the custom code below. (How to add custom code? ↗):

add_filter( 'woocommerce_get_price_html', function ( $price, $product ) {
    if ( class_exists( 'WPCleverWooco' ) && $product->is_type( 'composite' ) && ( $components = $product->get_components() ) ) {
        $product_id   = $product->get_id();
        $custom_price = stripslashes( get_post_meta( $product_id, 'wooco_custom_price', true ) );
        if ( ! empty( $custom_price ) ) {
            return $custom_price;
        }
        if ( $product->get_pricing() !== 'only' ) {
            $price = $product->get_pricing() === 'include' ? wc_get_price_to_display( $product ) : 0;
            foreach ( $components as $component ) {
                if ( ( $component['optional'] === 'no' ) && ! empty( $component['default'] ) ) {
                    // required and has default product
                    if ( is_numeric( $component['default'] ) ) {
                        // id
                        $product_default = wc_get_product( $component['default'] );
                    } else {
                        // sku
                        $product_default = wc_get_product( wc_get_product_id_by_sku( $component['default'] ) );
                    }
                    if ( ! empty( $component['price'] ) ) {
                        // has new price
                        $price += wc_get_price_to_display( $product_default, [
                            'qty'   => $component['qty'],
                            'price' => WPCleverWooco::get_new_price( $product_default->get_price(), $component['price'] )
                        ] );
                    } else {
                        $price += wc_get_price_to_display( $product_default, [
                            'qty' => $component['qty']
                        ] );
                    }
                }
            }
            return wc_price( $price );
        }
    }
    return $price;
}, 999, 2 );

Then, the composite's price will be calculated from the default product that you set in each required component: