It will be difficult to assist without seeing a workbook with at least some sample data. You may try reviewing this Think Data Thursday where Actions are reviewed in detail by one of our amazing Community Ambassadors - Simon Runc.
I hope this helps
So if i understand you correctly ...you are using the trick where you expose the "Actions" as filters on dashboard 2, and then want to fiddle with what is filtered from these filter versions of the actions, and when you do the sheets from the secondary/other data source aren't updating.
If that's the case that is a tough one! While we can pass filter values between datasources, it does generate a second set of filters (unlike everything else with Filter actions, "Apply to all related datasources" isn't one of the options we have.
We had this problem at my work recently. Our solution was by "hook or by crook" force the data sources together (even if it means an ugly union where only the common fields are lined up) ...it wasn't pretty, but did get the job done.
Post back and let me know if you are still having this problem, if I've understood it correctly and (if so) did you find a nicer solution than our one!