How to use a single reference entry for multiple custom groups in a single endnote library

I am currently using a single endnote library to manage all my manuscript writing.

For convenience, I create custom groups using lead authors.

For example I have Prof X’s publications as custom group 1 and Prof Y’s publications as custom group 2.

If there is a publication A that has Prof X and Prof Y as co-authors, I will copy the same reference to both custom group 1 and custom group 2.

As a result, I have the same publication with three difference reference number in my library.

One copy in All references,

One copy in custom group 1

One copy in custom group 2.

Is there a solution to use one copy of the reference in group 1 and group 2?

Thanks and regards,

LIM

The same record should be dragged to the two groups.  This doesn’t duplicate the record - you don’t copy and paste it, you drag it, and then it is one record but associated with both groups?