Hi. I have a flat data module at 'opportunity' level, with eg. column for 'division', 'dept', and lots of others at a very granular level (eg. by day). I have an aggregate module (eg. at division by month) derived from this detail module. In the aggregate module, I have a list selector that allows me to see division and all it's aggregations at the month level. What I want to be able to do is know which division is selected in the aggregate module, so that I can then filter the detail data to show the component detail data (in effect a drill through) that is used in the aggregate module. Because the detail data is very sparse, I do not want to put the division (ie. product) dimension on the detail module - what I'd like to be able to do is identify the currently selected division in the aggregate module, and then have a filter calc in the detail module that indicates whether the detail record is currently being used to display data in the aggregate module. I do not see a way to know which division is selected in the aggregate module (ie. the currently selected division in the list). I may be missing an obvious solution or approach, (or maybe adding the product dimension to detail is the only approach) but any thoughts or ideas would be greatly appreciated. Thanks.