How to show the products of product tab block
This is not only category products, please note this one
- New Product: your products have to new product, refer this article https://zemez.io/magento/support/how-to/magento-2-1-x-how-to-set-product-as-new/
- Sale Product: your products have to sale product, refer this article https://support.weltpixel.com/hc/en-us/articles/222779107-How-can-I-set-a-product-as-New-or-Sale-in-Magento-2#:~:text=Step%201.-,Go%20to%20Catalog%20%3E%20Products%20and%20select%20product%20to%20edit.,price%20and%20the%20sale%20interval.
and note that you checked category, so the products are belong to that category show only.