Hi I'm a spanish possible user. But I have a question
What code is necessary to be able to put a list of products inside the Products(Categories List) Block.
Only must to see the products of the selected category.
For example
Cat1
-Product1
-Product2
Cat2
Cat3
 
If Cat2 is seleccted
Cat1
Cat2
-Product1
-Product2
-Product3
Cat3

you can actually go to CMS -> Site Layout and find under 'Products Catalogue Layout' -> Products Listing Page. Once you added the categories list block, you can change the settings by clicking on it.