I realized I did not finish my sentence. I was saying that I cannot use global quick filters because dashboard#1 is entirely based on users selecting one or several graphical bars on multiple charts. Those are the filters that need to be passed on to dashboard#2. Hope it makes sense.
Why do you say that you cannot pass them to another dashboard? You should be able to select another dashboard as the target of an Action Filter.
Because I need to be able to first filter dashboard 1 before switching to dashboard2 which would then reflect the filters in place in Dashboard#1. That's why I made the comparison to a sub report which carries the parameters passed to the main report.
You could create two actions that cover the two destinations.
Alternately, you can limit the scope of global quickfilters by creating separate (duplicate) data sources - global quickfilters are only global within a data source.
If neither of those things satisfy, well you're just not going to get to your "sub report" concept in Tableau, sorry.