Sheet Summary Report with Dropdown


I'm creating a sheet summary report to use for a dashboard and have my source data broken out by phases. I'd like to be able to group the report data by phase, so I tried adding a single selection dropdown to the sheet summary. However, it's returning blank in the report. The source data is a project management / Gantt chart. My end goal is to use the summary report to build 4-5 pie or donut charts based on the data grouped by phase (chart per phase). Is there another/better way to go about this?