OpenERP provides a standardized search box in the top-right in all of the list and kanban views. Depending on the menu item, some forms come with predefined filters already set for the list.
If you navigate to Sales and select Customer, you can see the search box in the upper-right corner with the Customers filter preassigned.
Some lists open with a predefined filter that will limit the primary data set. In the prior screenshot, you can see that the list view Customers has a customer filter applied by default when you open the form. OpenERP stores customers vendors and employee information in the same central database table. The Customers filter prevents other types of data such as vendors or employees from displaying in the list.
In this instance, if you clear the Customers filter by clicking on the small close box in the tag, you will have a list with not just customers. Instead, OpenERP will return partners, users, suppliers, and contacts as well.