Hi Kristin,
Since you are using two separate data sources, the cascading filter approach is probably not applicable. Normally in your scenario you would simply point your Dimension Filter to the second data source via the Target Data Source property but this only works if the filter dimensions in both data sources are the same. So here is a script that should work for your case if you place it in the On Apply event of your Dimension Filter:
DS_2.setFilterExt("DELYEAR", DS_1.getFilterExt("0CALYEAR"));
Let me know if that works for you.
Regards,
Mustafa.