In another thread, @PeterPower asks about generating Family Group Sheets that are linked … or have linking IDs. (So that you can easily navigate between generations.) And that is covers all the Families (or a filtered subset) in the tree.
He wants to replicate a functionality in Sukujutut, a Finnish commercial genealogy application. (We’ll need an example to understand what form their format takes.)
I’m not adept at Gramps reports. Is this a feature of the Family Group reports? Or would it need a book with an index?