According to the dynamic category, products are generated automatically based on product attributes. One of the useful options Magento 2 Dynamic Category extension offers you is to preview products in dynamic category rule.

In order to preview products in Magento 2 Dynamic Category Rule follow these steps:

1. Go to Catalog > Dynamic Category > Rules.

2. Choose the Dynamic Category  Rule which you want to preview the products in. 

3. Scroll down to the Product's Condition and click Preview Products to see the products generated according to the rule.

Magento 2 Dynamic Category Rule Preview

Note: The preview option is available without saving. You're able to preview the products generated according to the rule even before the rule was saved. This feature allows you to make sure just the products you intent will be added to this or that category.