When we want to add folder to document library, it is a very basic step of creating folder. Now what if I say create a folder with metadata like the way we have for documents. Now this is interesting. Isn’t it?
There is no way by default to have metadata for folders. We create columns for document library that actually becomes metadata for documents and not for the folders.
So let us go ahead and create a custom content type. We cannot change default folder content type as it is sealed.
Go to site actions, site settings, site content types.
Click on create
Give a name advance folder and keep the settings like shown in figure below.
Click on ok and then click on add from new site column when you are on content type settings page.
And then add a column called department
Now go back to library, set allow management of content type to true from library settings , advanced settings.
Click on add from existing site content types
Select custom content type, select advance folder and add it
Now under New Document, you can find advance folder.
Once you click on it, dialog opens to create folder with a column that we had specified earlier.
Once you add that then you should be able to view the folder in library and by editing its property you get to see the department column in that.
Hope this helps.