You need VLF EPC141006 (or later) to use this feature.
The None option prevents the tool bar from being displayed above the instance list.
The Top, Left, Right and Bottom options are all treated as Top.
Note that hiding the toolbar may not free the space above the instance list because other options also appear in that area.
Set this option to Top, Left, Right or Bottom to cause a tool bar of the commands associated with objects in the instance list to be displayed in the specified location. Set this option to None to prevent an instance list tool bar from being displayed.
The existence and location of any instance list tool bar is an application designer controlled feature.
This option only applies to the shipped instance browser.
This property is in the Business Object Instance List tab.