How can I extract content from sub summary layout objects using GetLayoutObjectAttribute?

[ggt667]

How can I extract content from sub summary layout objects using? https://fmhelp.filemaker.com/help/16/fmp/en/index.html#page/FMP_Help/getlayoutobjectattribute.html

I'm able to grab the content from the first subsummary, not the remaining however.

The following:

set field( output;
  GetLayoutObjectAttribute( 'header', 'content' ) & 
  GetLayoutObjectAttribute( 'row',    'content' ) & 
  GetLayoutObjectAttribute( 'footer', 'content' )
)

works fine, the bad thing is that only row 1 finds its way to the output-field.
 

Edited November 22, 2017 by ggt667