Untitled

<body>
    <attribute name="class" value="page-product-grouped"/>
    <referenceContainer name="product.info.form.content">
        <block class="MagentoGroupedProductBlockProductViewTypeGrouped" name="product.info.grouped" before="product.info.addtocart" template="Magento_GroupedProduct::product/view/type/grouped.phtml"/>
        <container name="product.info.grouped.extra" after="product.info.grouped" before="product.info.grouped" as="product_type_data_extra" label="Product Extra Info"/>
    </referenceContainer>
    (...)
    <referenceBlock name="product.info.details">
        <block class="MagentoCatalogBlockProductViewAttributes" name="product.attributes" as="additional" template="Magento_GroupedProduct::product/view/type/grouped/attributes.phtml" group="detailed_info">
            <arguments>
                <argument translate="true" name="title" xsi:type="string">More Information</argument>
                <argument name="sort_order" xsi:type="string">27</argument>
            </arguments>
        </block>
    </referenceBlock>
</body>

$_product = $block->getProduct();
$_associatedProducts = $block->getAssociatedProducts();