Select the top book node, and click and select Add Child, and then select Section.
Select an existing artifact or section, and and select either Add Above or Add Below and then select Section.
In Add Section dialog box, provide a Name of the section.
Optional: To set a POV for the Section, click Select Dimensions.... In Dimension Layout, under POV bar, click Add - , and select the required dimension from the drop-down list, and then click OK.
If a Section contains reports with multiple data sources, you need to add the data source in the Section’s Actions menu and select Manage Data Source. The available dimensions in Dimension Layout are based on the first data source appearing in the Manage Data Source dialog.