By default, the structured data content for a chosen asset will not be present within an Index Block rendering, or through the generated system-data-structure within the DEFAULT region if no Index Block is assigned. Instead you will see an empty <content/> element.

In order to include this content, edit the Data Definition containing the chooser field, open the chooser field's settings and set the Render Content Depth field to a value of at least 2.

Note: Depending on the structure of the chosen asset, a higher value may be required.