Wholesaler has two types of discount you can apply to merchants.
Discount for each product (Local discounts)
Those applies per product, so each wholesaler tag can have a different price for each product. Also, it also means you can offer just some products as wholesaler products.
For example you can have the large_wholesaler group which can buy t-shirts at a wholesale price, but the other products will be at the normal price. The Default Discount option will enable you to quickly set prices
After you have created a group like this, you will have to put the prices for each product you want wholesalers in this group to see. If you don't set a price, they will see the regular price.
To set prices for a product, navigate to the Product tab and select the product you want to change:
If you click on set to X%, all prices in that column will receive a X% discount over the retail prices (in our case, the Large wholesale will get a 75% over 10€, for a final 2.5€ price). You can also manually set the price you want for just one variant.
Changing each product manually can be cumbersome, that's why you can also do bulk editing of your products in the tab Import & Export.
Those are flat percent discount over ALL items. Wholesalers in groups with Global discount will see their prices drop the % you specify all over the page, so be careful when using this option
In this example, the wholesaler will see a 99% discount in each and every item.