This is a very interesting scenario. I'd love if you could share some details on why you're using a hidden folder in this manner as I might want to, too :)
As for how to do this, you need to use a hidden-gem of a keyboard shortcut that I learned from Finder: CMD-Shift-G will open the Go to Folder window. To use this, click the + button and select "Encrypt single folder.." to create a new protected folder, and when prompted for the folder's location, press CMD-Shift-G, and enter the path to the hidden folder, as shown in the first screenshot.
After clicking "Go", the contents of the entered folder will be shown, and selecting "Choose" will start the protection process, as shown in the second screenshot.
I hope that helps. Please let us know if you have any further questions, and please do let us know how you're using hidden folders in your workflow.
Edit: My attachments are appearing in the wrong order. In the future I will try to remember to upload them in reverse order :)
As for how to do this, you need to use a hidden-gem of a keyboard shortcut that I learned from Finder: CMD-Shift-G will open the Go to Folder window. To use this, click the + button and select "Encrypt single folder.." to create a new protected folder, and when prompted for the folder's location, press CMD-Shift-G, and enter the path to the hidden folder, as shown in the first screenshot.
After clicking "Go", the contents of the entered folder will be shown, and selecting "Choose" will start the protection process, as shown in the second screenshot.
I hope that helps. Please let us know if you have any further questions, and please do let us know how you're using hidden folders in your workflow.
Edit: My attachments are appearing in the wrong order. In the future I will try to remember to upload them in reverse order :)