In Endnote, only Groups can be shared between users. If you have references in a Smart or From Group that you want to share, you must first move those references into a Group.
Identify the Smart or From Group you want to share and select all the references in the list.
Right-click (Ctrl+click on a Mac) and select Add References To.
Either select an existing Group or Create Custom Group to add references to a new Group. (NOTE: This new Group is a static group and will not automatically update like the original Smart or From Group.)