Hi there,
So you are trying to just have 1 page, with a list of categories, and then in each category item on that page you list the child articles? So you have a "list within a list" on the same page?
If this is what you are trying to do, then it is not currently possible to do this all on the same page with SEBLOD.
If you just want to have a page of categories, then you click a category and get a list of child articles for that category, then this is easily achieved using Live values, which I describe how to use here: http://www.seblod.com/resources/videos/creating-list-pages-in-joomla-with-seblod-s-live-plugin
Cheers,
_jrmo