The search bar lives in the document list, and is made of a search field and several restriction buttons:
All: Displays all documents in the document list
Today: Displays all documents created in the last 24 hours.
This Week: Displays all documents created in the last 7 days.
This Month: Displays all documents created in the las 30 days.
Draft: Displays all draft documents.
Final Displays all final documents.
Search Field: Allows you to search through your documents.
You can seach your documents by: Number, Name, ...