Pega Customer Service uses the Pega Platform search facility for work objects and case data. Pega Customer Service searches for your work types and other objects only if they are listed on your application rule or an inherited application rule. 

When a user selects a work object or case from the portal search results list, a tab opens in the general work area using the Review harness for that work type.

For more information on enabling search of work data for your application, see the Pega Platform help.