Full-text search box on top of user portal is handy way for searching cases quickly. However, sometimes you may find the search results screen does not provide you enough information to identify the case your are looking for. For example, when multiple customers share the same name, it becomes difficult to distinguish their cases in the search results. This is because the full-text search results do not display the customer's home address. While the "Preview" panel can be used to identify the correct case, it becomes cumbersome and inefficient when there are many results with the same customer name. You can enhance the full-text search results to include the customer's home address. This will make it easier to identify the correct case directly from the search results, improving user efficiency and accuracy.

For detailed configuration steps see below article. 

https://support.pega.com/discussion/constellation-tips-display-custom-property-values-full-text-search-results