This tutorial explains how to create a shortcut (modifier key) to open a specific folder in the Finder of OS X using Automator.
Automator allows you to automate repetitive tasks (create workflows) in other programs (Finder, Calendar, Safari...) installed on your Mac. We will create a service that will trigger specific folder actions in the Finder, which in our case will open the selected folder and display its content in the Finder menu. Once done, we will assign a keyboard shortcut to the launch the selected service. The method described below is the same for most versions of Mac OS, including Mac OS X 10.10.4 Yosemite.
Go to the Application folder and launch Automator. You will be prompted to choose a template for your workflow, click on Service > Choose.
Click on the Services receives selected menu and select no input , and next to in select any application. Basically it should look like this:
Services receives selected no input in any application
Go to the Actions column located to the left select Files and Folders. Move to the middle column, drag and drop the following tasks to the right pane: Get Selected Finder Items and Open Finder Items.
Click on the File menu > Save As and select a name for the new service. The new service will be added to the Services folder in your Library, you can now close Automator.
Assigning a Keyboard shortcut
Click on the Apple menu > System Preferences > Keyboard > Shortcut. Select the Services section and select your new service. Assign a shortcut to the service and close the System Preferences window.
Testing your new shortcut
If the shortcut won't work, try to activate it by launching the service at least once using the Finder. Open the Finder > Service menu and select the service.
If the problem persist, then you need to check for conflicts with an existing shortcuts and make the necessary modifications. Some shortcuts won't work no matter what, in such situation you simply need to test other combinations until you find the right one.