Help with linking cell to a filtered spreadsheet

Hello! Struggling to find the best words to describe what I'm trying to do, but here's my best effort:

 

I am working in a workbook with two sheets. Sheet 1 = a spreadsheet of information about events that my firm has done (including the name of the practice group in charge, whether firm hosted or sponsored it, and which city hosted it). Sheet 2 = a chart of various statistics (for example, showing how many firm-sponsored and firm-hosted events were done in a given year, separated by both office and practice group. I am looking for a way to automatically link the statistics chart to the spreadsheet of data, so that when a new firm-sponsored event is added for the tax group in NY, for example, the numbers in the chart update accordingly. My problem is that I can't link directly to the spreadsheet because it first needs to be filtered for the appropriate practice group, office, and type of event before I can find the total number of events. Does this make sense, and does anyone know if it's possible to accomplish this?