The Bid Navigator, located to the left of the main display window, acts as a database and bid organizer. The Bid Navigator is set up in a folder tree structure with bids appearing directly below their parent databases. You can have up to 15 databases open at one time. See Databases, Opening a Database for information on opening and closing databases.
Use the Expand 
and Collapse 
buttons to help you navigate the databases
and bids within them.
Closing the Bid Navigator does not affect which databases are open.