Hello @Francesco1990, from what I understand this app may work for you : https://apps.shopify.com/frequently-bought-together?surface_detail=frequently+bought+together&surfac...
It shows up as bundles in each product page as well as splits up individually in cart page. Hope it helps.
That is an interesting conundrum you have there!
We would recommend that you check out our apps on the Shopify app store: Simile.
Simile smart bundles have different plans that allow for more functionality and customization. If the features do not meet your needs
you can always reach out to our developers for a more customized solution!
Hope this helps!