Jeff,
This should be doable, but if your first chart’s model is an aggregate model, the “list of Id(s) in context” approach won’t work. Let’s say your two models are named OppsAgg and OppsDetail. OppsAgg is summing Amount (alias sumAmount), grouping by StageName (alias stageName). OppsDetail has a Filterable Default Off condition named StageName, and has Load Model data on page load unchecked. Rather than using Context Conditions to filter out rows, you’re going to need to set that StageName condition and requery that OppDetail model as a part of your Series On-Click action. After that requery, display the popup which contains the chart on the OppsDetail. Something like this:
Side note, here’s a good thread on the $Chart merge variable. Does that help?
