
Note: We're starting with the title page created in this article: Creating a Title Page in Writer from Document Properties
First the title should be styled as a title, to do this:
Click the Style drop-down and select More...

In the Styles and Formatting dialog, click the drop-down at the bottom and select “Hierarchical”

In the Styles and Formatting dialog, under Heading double-click Title

Next we select the subtitle, author and date in the document (don't close the Styles and Formatting dialog)
In the Styles and Formatting dialog select Subtitle

Our document should now look like this:

To close the Styles and Formatting dialog, click the close button at the top-right corner of the dialog.