From Documents application

I go to Directories and I create the directory Tasks Documents.

I check the option Is Root Directory, then I choose Attachments Storage as a Root Storage for this Directory.

I click in the Smart Button Files to create a File in this Directory.

I realize than I can create an attachment of type URL.

From any application

I go to the a view then I click on the icon attachment to display options.

I choose Add URL.

I enter the name of my document and the URL to this document.

The URL is added to my object as an attachment.

Now I go to the application Documents, menu Directories and I choose my directory Tasks Documents already created.

I can see that the Task is added as a subdirectory to my directory

When I click on the button Files, I can see my attachment of type URL is added to the directory.