Trying to populate choices in drop down on PowerApps based on SharePoint People Picker field

I have a PowerApps app that connects to a SharePoint list. There is a column, Approver, that I want to use to filter a report. Approver is a People Picker field. I want to have a drop-down input box on my PowerApps screen that has the names of Approvers from the SharePoint list, so that I can filter the results based on approvers rather than typing in a name from the GAL. Is this possible, and if so, any tips on how to do this?