Have you noticed this. When you are searching for a keyword Google shows the other relative keywords in its left corner below the search tools.
In this screenshot, when we search for Ecommerce Solutions we can get the other suggestions like website design, website development and more. And in the following Screenshot
when we search for SEO services we can get the other suggestions like PPC Management, Search Engine Optimization and more.
Usually it shows other keyword suggestions related to the keyword down the SERP.