You want to add multiple sections to your Document Designer template, and you want the...

Select the Child Section check box in the Section Properties panel for each subsequent section following the first section in the series.

Add each section to the template and manually remove the page breaks at the end of each section.

Add the first section in the series and select the Continuous Section check box in the Section Properties panel.

You do not have to do anything because this is the default behavior in Document Designer.

Select the Continuous Section check box in the Section Properties panel for each subsequent section following the first section in the series.