Thats called an Perspective... if you would read the guide i linked to carefully you'll see its what you're asking for "How to Display Elements in Custom Perspectives".
A perspective is technically just the root-element of a tree. Normally when you create trees you attach it to ie. Content, but if you attach it to Root you'll in practice get a new perspective..
A perspective is technically just the root-element of a tree. Normally when you create trees you attach it to ie. Content, but if you attach it to Root you'll in practice get a new perspective..