Global Search is an awesome feature of Salesforce, you can search everything in your Salesforce org, from Account, Contact, User (People) until Chatter. You also can use Options to search only "Limit to items I own" and "Exact phrase".
But, one thing that many user do not know that we also can filter search result. How?
By default, you will not see Filter in the search result. Your Salesforce admin need to set specified fields to use as filter.
Example for Account, go to Setup - Customize - Accounts - Search Layouts. Then look for 'Search Filter Fields' and click Edit link. Admin can select fields want to show as Filter in the search result.
Screenshot below show, user can filter on Account, but not on Contact. This is because admin has set fields for Account Search Filter, but not for Contact.
Once you click Show Filters link, you can enter any search criteria.
Note: if you leave the field blank, it will not use as search criteria.
The criteria you specify are AND based. That is, if you specify more than one criteria, the result includes only records that match all of the criteria. For example, if you enter 'acme california' in the Account Name filter field, your results include account with contain both acme and california. So 'acme california' and 'california acme' will return the same result.
For date field, such as Created Date, you can enter literal date values such as YESTERDAY or NEXT MONTH.
Reference: How Do I Refine Search Results?
Last update: 8 May 2016