# Further collection questions: "next"/"prev" for deeper sub-folders

So far I am moving good into Grav. Now one of the “books” I have has a deeper structure:

`\default.md` then I have `01.toc`, `02.preface-tr`… corresponding to different chapters in the book. Then, for `04.01`, I should have 3 sections of that chapter: `01`, `02`, `03`.

Now the issue is: the “next”/“prev” works only on one level: `toc -> preface-tr -> preface -> 01 -> epilogue` per se. I want to have `01 -> 01.01 -> 01.02 -> 01.03 -> 02.01 .... -> epilogue` kind of navigation.

I know I may counter this by moving the structure `04.01\01` up one level and make it `04.01.01` but this may make my folders too many.

Any best practice?

Can anyone help on this?