I can see the purchases vs. returns on the Performance tab in Vanguard but that is for my retirement and brokerage accounts. I'd like to see that breakdown for just my brokerage account. Does anyone know how to do that?
You can use the 'My Accounts'->'Cost Basis' link to see the total cost and profit/loss on a per investment, per account basis.
If you click through to the "Personal Performance" tab (this url or a similar one), you see that same chart as before; but you now have a section that can either select accounts, or holdings, and allows you to click checkboxes for whichever you want to see on the chart, then 'update chart' to get the chart for just that account/holding.