Apart from using the Search Field to perform search operations, you can also perform column-wise search from the requests list view page, if you know any of the request detail such as subject, support rep assigned to the request and so on.
To perform a column-wise search,
From the request list view page, click on Search icon . The search field opens just below every column that is visible in the list view.
Enter the search string in the column of your choice.
Click Go. The search results matching the search string(s) are displayed.
1. The search would return the results for any of the text fields of the request.
2. You cannot search for a request based on any of the date fields of the request.