They way I would approach this is similar to this community case here: button to go from one dashboard to another .
As well as looking into this product help for additional reference.
I essentially would make a table of contents for the selection you would like that would then navigate the person to the desired dashboard. You can in-turn set a button on the dashboard they navigate to that would return them to the starting dashboard. Similar to what is used in this presidents of the United States viz: Bits of American Presidential History | Tableau Public
If you notice at the top left it says 'Test Drive a Prez!' if you click on the button, it will navigate to a new dashboard. In this particular use case they only have two separate dashboards. But you are able to use as many as you would like.
I believe the above information will help guide you to a resolution. Please let me know if you would like clarification on anything.