Hi there,
Thank you for reaching out!
I understand that you’d like to modify product categories so that one category includes all products of the same author.
It might be best to reach out to the support team of your multi-vendor plugin for recommendations here since product category taxonomy is not designed to work like this and by default, you could only add products of a particular vendor to a particular category manually one by one.
It might be possible to customize the code on your site so that a particular category only shows products of one vendor despite other products being in that category or not all products of a particular vendor being in that category, but you’ll need a developer who is familiar with your multi-vendor plugin.
If you decide to pursue such functionality and find yourself in need of help with the code – I’d recommend reaching out to someone from WooCommerce.com customizations page:
https://woocommerce.com/customizations/
