I would like to export a PDF with two different layouts: One for Desk and another one for Mobile.
The idea is that the PDF itself shows one layout or another depending which device are you using to open the PDF file. Could be possible?
I have created two alternative layouts but not sure if that could be done. Maybe need a script.
Can't be done. There is no such thing as a mobile PDF or a desktop PDF. The PDF format is not responsive.
Even with inDesign?
Is there some reason you thought this was possible? Did you see it done?
It's entirely possible to server different web pages according to whether you are on a mobile device. Hence, you can make two different PDFs and link to them.