Hello, I can´t find any module that can do this.
I want a module that can make packs, for example, buy this jacket and the pants are with a discount of the 20%... like in the image attached:
I suggest you having a look at the Bundle Product Promotions extension that helps to create product packs with fixed quantities and prices. You can apply 3 pricing rules based on the package price, package discount, or bundled products' prices.
There is one more option. The Grouped Promotions module creates discounts for certain sets of simple or configurable products within a grouped product. Several promotion rules are also available.
Hope this helps!