When exporting Items with Sub-Items, the fields you want to see in your exports need to be visible in the
Sub Items tab.
This applies to
Export > Export to Word,
Export > Export to Excel and
Export > Office Templates > Export to Roundtrip.
In these exports, fields will not be exported unless they are visible in the
Sub Items tab, even if they are visible in the parent Item view.
The
Sub Items tab is critical for configuring export fields and is located in the parent Item's View, on the left.

To set the fields you want to export, you need to have the
List View selected in this tab.

By clicking on the cog you will open a window. Here, fields can be selected or de-selected according to what you want to see in the export.

All fields selected will be visible in the
Sub Items tab and will be exported, even if they do not exist in the parent Item.
As opposed to the
List View, the
Reading View fields are not configurable and the cog is not visible when the
Reading View is selected.

Exporting Items with Sub-Items while in
Reading View will only export the fields
Headings,
Id,
Name and
Description.
In
Export > Office Templates > All Items Details export, the described behavior does not apply, since the parent Item fields are exported instead of the
Sub Items tab fields.
Also, the
Office Template Coverage Explorer export, due to its nature, it is not influenced by the
Sub Items tab in its fields, and the same goes for
custom templates.
#OfficeTemplates