Using the <<subitems_header>> and <<subitems_body>> placeholders in your document template, you can have DocuGen insert the subitems from your board, specifically the subitems belonging to the row that generated the document.
Example: Suppose your board has subitems with many columns, but you would like to display just four of those. You will need to go to the DocuGen view and tick the checkboxes for the four columns under the section 'Subitems styling':
Then copy the table immediately above this list:
... and paste it into your document template:
You can also style the table as you wish, for example by changing the font, styling (bold, italic, etc.), text color, cell shading, text alignment, column widths, etc.: