Not sure what you are trying to say here? If you create a user defined category or tag and then do a search specifying that value Calibre already shows all the books that meet the search criteria.
You can save searches under a user defined name for later re-use.
You can also use a search as a "restriction" which means that until you lift the restriction all operations are limited to those books that satisfy the restriction (.i.e. it acts like a virtual library).