Searching in Find Mode 
Use the Find mode to search for existing data, such as business partner or employee records, item details, and sales or purchasing documents, in SAP Business One. Searching in the Find mode is similar to searching in the Add mode, see Searching in Add Mode.
Procedure
Use the example below to search in the Find mode.
Choose
Business Partners 
Business Partner Master Data 
.The Business Partner Master Data window appears in the Find mode.
Enter search criteria as follows:
Enter the first character of the business partner code or name, followed by an asterisk (*), for example, A*. Choose Find, and select the relevant business partner code from the list that appears.
If you know a partial business partner code or name, place it between asterisks (*) and press Enter to display a list of all the records that fall within this range.
If you know the full business partner code or name, enter it and choose Find to display the appropriate details in the window.
Fill in multiple fields to filter the search.
Once you have found a relevant business partner, you can view or update the business partner details.