Is this still an outstanding question? I looked at the workbook, but I'm not sure exactly what the actual versus expected result is based on the packaged workbook.
At present, I see one dashboard which is only going to display that page and shouldn't change layout orientation by selecting a mark in the view. It sounds like you may want to drill through to see only one sheet based on user interaction, which I think would be something that can be accomplished using actions to open a sheet separately from the dashboard. Similarly, the orientation of the page can be changed in the Dashboard Device Preview options; the orientation will not rotate automatically. Create Dashboard Layouts for Different Device Types - Tableau
For the dashboard to rotate to a different orientation automatically without turning the device would be something to post about in the Ideas forum.