YITH WooCommerce Multi Vendor allows you to turn your store into a marketplace where vendors manage their own products and earn a commission on every sale.
The integration with YITH Dynamic Pricing and Discounts gives you the possibility to create custom discount rules for all the products associated with one vendor or to provide a discount for all the products of the shop except for those linked to a specific vendor.
Just make sure you have installed and activated the premium version of both plugins.
Then, whenever you create a price rule, you will be able to restrict it to products by one or more vendors, whether it is a Price rule…
… or a Cart discount rule:
For more details about YITH Multi Vendor plugin, please, refer to the plugin official documentation.