How do I reference metafields of a nested metaobject?

Hi. I have a metaobject which provides five file inputs (Images). This metaobject is a metafield of a product. Overview:

Product

Product Metafield

Metaobject

Metafield 1: Image

Metafield 2: Image

Metafield 3: Image

Metafield 4: Image

Metafield 5: Image

Names

Product Metafield (that hosts the metaobject) product.metafields.custom.old_images

Metaobject: old_images_linking

Image 1 - 5 metafields within metaobject: image_1, image_2 aso.

I want to write a custom liquid code on the product default template in the shopify theme editor. Within this custom css I want to have an if function, that hides #shopify-element-xxx if the metafield image_1 of the metaobject that this product is connected to is empty.

I know how to write the code. But I need help understanding how I specifically target this field.

So far I have tried

{% if product.metafields.custom.old_images.old_images_linking.image_1 == blank %} etc…

But this is not working.

Anyone help? Thank you !