Product attribute group inside product attribute group

Create a product group and create an attribute into that specific group…it’s quite easy in magento.

Ex :

public function createAttributeGroup($groupName,$order = 1)
{
    $attributeSetId = $this->product->getDefaultAttributeSetId();
    $attributeGroup = $this->attributeGroupInterfaceFactory->create();
    $attributeGroup->setAttributeSetId($attributeSetId);
    $attributeGroup->setAttributeGroupName($groupName);
    $attributeGroup->setSortOrder($order);
    $this->attributeGroupRepository->save($attributeGroup);
}

This is working fine and you will see a new fieldset in the product form page with the new attributes.

        $eavSetup = $this->eavSetupFactory->create(['setup' => $this->moduleDataSetup]);

        $this->createAttributeGroup('Ingredient INCI',10);

        $attributeCodes = [
            'ingredient_inci_1',
            'ingredient_inci_2'
        ];

        foreach ($attributeCodes as $k => $attributeCode){
            $eavSetup->addAttribute(
                Product::ENTITY,
                $attributeCode,
                [
                    'group' => 'Ingredient INCI',
                    'type' => 'text',
                    'backend' => '',
                    'frontend' => '',
                    'label' => 'Ingredient INCI '.($k+1),
                    'input' => 'select',
                    'class' => '',
                    'source' => Inci::class,
                    'global' => ScopedAttributeInterface::SCOPE_GLOBAL,
                    'visible' => true,
                    'required' => false,
                    'user_defined' => false,
                    'default' => '',
                    'searchable' => false,
                    'filterable' => false,
                    'comparable' => false,
                    'visible_on_front' => false,
                    'used_in_product_listing' => true,
                    'unique' => false,
                    'apply_to' => ''
                ]
            );

But what I would like to achieve is to set extra fieldsets into the main one.

Meaning i would like to go from something like that

To something like that where INCI 1 / INCI 2 would be subgroups of INCI

Sadly I haven’t been able to find any way to do this in the product page.

Any idea ?