This page tells you how to create:
EndNote is able to create groups which allow you to organise your references into subsets without the need to create separate EndNote libraries.
Groups can be renamed or deleted. They can also be moved into different group sets by dragging and dropping. References can be deleted from a group but they will always remain available in All References. The same reference can be added to several different groups.
Adding a new Group Set
It is recommended that you create a group set first.
From the Groups menu choose Create Group Set, or you can right click on My Groups and select Create Group Set. This will now appear in the My Library column. Give the Group Set a name.
Adding a new Group to your Group Set
Right hand click on the group set and select Create Group. Name your group as desired. You can create several groups under a group set.
To add references to a group, select the required references, go to the Groups menu and select Add References To and then choose the required group. You can also right click on the selected references and select Add References To and choose the required group. Alternatively, you can drag and drop the references to a group.
To create a Smart Group, right click on the group you would like your smart group to be placed and select Create Smart Group. A search box will appear. Enter a name for your smart group, then enter your search term(s) (it is useful to give your smart group the same name as your search term). Click Create. Your new smart group will appear under the Group Set with the retrieved references. Alternatively, open the Groups menu and select Create Smart Group.
To edit the search terms for the Smart Group, right click on the group name in the Groups Pane and select Edit Group. Make your changes and click on Save. Smart groups can be distinguished from other groups by the magnifying glass icon next to them.
When new references are added to the library, they are searched by each of the smart groups. If the references fit the search criteria they are automatically added to that group.