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 & 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.