Zend certified PHP/Magento developer

Magento 2. Show System Config Field Only In Certain Websites

To better understand what I mean by a ‘System Config Field’ check the picture bellow from here
enter image description here

I already know that I can configure the visibility of a Field based on the scope (Default/Website/Store/Store View).

I also know that I can display a field based o a value of another field (depends).

What I wish to achieve is display fields only in certain websites. (Imagine a multi-website setup).

I don’t expect this to be possible without custom development (would be great if it did).

So I’m asking for an entrypoint to the logic that decides whether or not to display a field base on the current scope (Default/Website/Store/Store View)?

I reckon it should not be that difficult to plugin that logic to check the selected website.

Any hint is appeciated. Thanks.