I am used to organising my Endnote Library by adding keywords to each reference and then setting up smart groups that automatically show all references I have with specific keywords.
I also use specific keywords to identify references that are relevant to each project I am working on and create a smart folder for each project. This makes it easier to sort references I want to share with specific groups of collaborators.
However, when it comes to sharing smart groups, this is not yet possible. Only static groups can be shared at the moment.
Please consider including this feature in future releases of the software.