"Related searches" option that was launched by Google in October 2009 has now been quietly removed from the search tools menu. The related searches option appeared within the Google search results page.
When related searches option was launched, it appeared on the left-hand side under the "standard view". But, the placement changed over the years with Google moving the whole search filters to the top in November 2012.
Google said that it wasn't seeing enough usage of related searches filter to keep it in the toolbar. But, the feature has not completely gone. When it is relevant, the related searches will appear directly within the search results, may be at the bottom.
Google has already said, "we do display related searches at the bottom of the page when they seem relevant enough.” For marketers, related searches was a useful and related keyword tool.Google Removes Related Searches Filter!,