Please add my vote for Dashboard Slicers.
Workaround:
1. I created a "picker" sheet for users to change multiple dashboards by changing a single cell on the sheet.
2. The picker sheet provides cells to identify the "current" and "-1 previous" value.
3. All sheets need a common identifier, date, class, number?
4. All sheets need a helper column (DV) to mark the column "YES" when the sheet column matches the picker.
5. The DV column is used on sheets and reports.
6. Change the picker value, updates all synced sheets, reports, and dashboards.
I have three "pickers" that update 26 sheets, reports, and dashboards.