The current search bar design has search type filter tabs that allow the visitors to search for various result types. We looked at the site analytics and learned that site visitors are not using the filter so we are considering simplifying the search bar visual by removing the tabs.
When we tested the simplified search bar design via usertesting, we learned that even though the users like the new look, it's not as easy to identify what they can search for (compare to the design with filter).
I am wondering what are some of the ways to educate the users about possible things to search? I know that search placeholder text is one of the ways but can't think of other ideas at the moment.