When I filter Scenario1 on dashboard containing VIZ-1 and VIZ-2 - it does not work. It works only on VIZ - 1
but I want it to work on VIZ - 2 as well
Scenario 1 is primary data source for VIZ - 1 and secondary for VIZ-2
But when I open the respective worksheet say VIZ-2, then scenario1 works but on the dashboard it does not
Attached sample Tableau workbook.....
Please be kind to help .......

I created one Excel workbook with 2 sheet, but if you have data on 2 different Excel workbooks it's also fine. You can add 2nd file on the same data source as same step as you use cross database join.
Though when you have 2 of Tableau data sources, or using published data source you cannot construct Relationship data model. Relationship must be defined in a single data source.