David Powell

Retain Author allows you to force your “next” and “previous” blog posts to stay within the same category and the same author.

Retain Author

Prevent mixing authors in your next and previous post links.

starblank

This free plugin shows next and previous product in single product view in same category.
Installation
Simply upload the .zip file into wordpress, then activate the plugin. A new submenu called Next/Previous Product will on Woocommerce Options left bar. 
This plugin requires Woocommerce in order to run. 
Has been tested with the new Storefront Woocommerce theme and is fully compatible with DIVI framework.
How to use
–Free Version allows: 
Show the previous and next product on the single product view of your store, from the same category, on the top the page.
—<a href="http://starblank.com/en/next-previous-products-for-woocommerce-premium/" rel="nofollow ugc">Premium Version allows:</a> 
-You can choose the location of the next /previos product links: 
 * Over the product 
 * At the bottom of the page 
 * Over the product description 
 * Below product description 
 * Floating in both sides of the screen
-Choose what product will be seen: 
 * Show only products from same subcategory 
 * From same category 
 * Show random products
<ul>
<li>
Show the image and/or the title of the product, all fully customizable in color and size
</li>
<li>
Allows you to use custom arrows instead of default ones
</li>
<li>
and much more!
</li>
</ul>
<a href="http://starblank.com/en/next-previous-products-for-woocommerce-premium/" rel="nofollow ugc">You can get the premium version here</a>
Have fun!

Next / Previous Product for Woocommerce FREE version

This free plugin shows next and previous product in single product view in same category. Installation Simply upload the .

Retain Author vs Next / Previous Product for Woocommerce FREE version