Thanks to a comment from Steve, you can just right-click on the tab of an open file and select open containing folder. One of those hidden features. So digging in a little further I found that you can map it to a keyboard shortcut File.OpenContainingFolder.
I was trying to figure out how to get to an existing directory in explorer for a file from the solution explorer via a shortcut key. Here is how I did it.
I created a new external tool and set up the following properties.
Then I added it to a global shortcut key.
That is it. Pretty simple huh.