When Acrobat merges PDF, how to ensure that the chapter mark of the PDF file exported by ID is kept

[dublove]

When Acrobat merges PDF, how to ensure that the chapter mark of the PDF file exported by ID is kept and not lost?

I now have three files
Nature and Geography-1.pdf　 Chapter Mark A
Nature and Geography-2.pdf　 Chapter Mark B
Nature and Geography-3.pdf　 Chapter Mark C
After merging, it seems that the chapter mark of the previous PDF will be used by default.
I want:
Three PDFs are merged with Acrobat, how to ensure that they still retain their own chapter marks

[Laubender]

Hi 喜狼_edny,

will it work if you move all three InDesign documents to a InDesign book file and export one single PDF file from there?

Regards,
Uwe Laubender

( ACP )