I came up with a quick test. I have a list call Employee with department column for employees in the company.
1) I created qSelector, qCharetview and qListView .
qSelector is based on Department column of Employee List.
qChartview is also based on Employee List and filter that is searching on department column.
qListView is based on Employee List with CAML filter.
2) I created session for qSelector (Session Name = selectorSession) and qChartview ( Search Session Name = chartSession).
3) I picked a department(HR) in qSelector.
I also picked a department(Finance) in filter of qChartView. The chart displyed fine with just showing the employees in Finance department.
4) I created a CAML filter in qListView as below to test the filter of employees by their departments from what the user has selected in above qSelector and qChartView.
<Eq>
<FieldRef Name='Department" />
<Value Type="Text" Source="Session" SourceName="Department" SessionName="selectorSession" SiteUrl="." Listname="Employee" />
</Eq>
It works. Returned rows of employees in HR department.
<Eq>
<FieldRef Name='Department" />
<Value Type="Text" Source="Session" SourceName="Department" SessionName="chartSession" SiteUrl="." Listname="Employee" />
</Eq>
Does Not Work! Hoping to see employees in Finance dept. But no records were returned.
This query works with referencing session object of "selectorSession" – it can retrieve the values in that session.
but does not work with referencing sessionName = "chartSession". Returns no rows.
Conclusion: you can pass parameter values and retrieve values in other filters using qSelector session but not with Search Session for chart filters.
Hope I am right. maybe someone can verify that.
-Myo