leaflet - Get popup info in multiple layers from one click

I have multiple layers, say a site location as a marker and a town location as a polygon. I want to be able to click on the marker and push it's attributes to a dialog, and also send the polygon's name attribute to the same dialog.

So I need to get both layers information from the same click. The marker is easy and in it's onEachFeature I can run an on-click function, but how do I fire off the click for the second layer by only coordinates?

End result would be a dialog with a tab for each layer, to show it's information.