There are several potential ways to do this. Here are steps to do this the easiest way:
1. Create a sheet called "Clear Filters".
2. Create a calculated field called "Clear Sheet".
3. Place the new "Clear Filters" sheet onto your second dashboard.
4. Create a filter action that runs from the "Clear Filters" sheet and targets all sheets on the other dashboard.
5. Select "Selected Fields" from the "Target Filters" menu at the bottom of the dashboard action interface.
6. Go to "Add Filter" and input "Clear Sheet" as your Source Field, and anything else as your Target Field.
7. This will cause Tableau to clear the dashboard the first time you click on your "Clear Filters" sheet, and everything will appear again on the second click.
I have attached an example workbook for you to reference.
Also, here is an additional link that addresses the topic:
Clear Filters Example.twbx 2.1 MB
Like Russ was saying it could be done but with some limitations as there hasn't been a direct solution from Tableau. For example if your field that needs to be reset is a NAME with the filed type as wild card you cannot automatically reset it using reset filter instead you need to manually reset it. But in case your field is a drop down it would automatically reset to the default value of ALL.
So in short if all your fields are drop downs having a default value the solution will work as expected else there could be some hiccups. Let us know if it worked for you.
I have built it as suggested however I have two issues.
1) When clicking on clear filters it navigates me back to my first dashboard, I do not remain on the second one.
2) Because of #1, the whole first dashboard is empty (after first click).
You'll need to edit the target sheets on your Dashboard Action to target the sheets on the second dashboard, and not the sheets on the first dashboard.
Hopefully this fixes the issue.