The group feature is extremely useful for keeping track of a large number of papers. However, one often needs a separate library for a new project (e.g. a shared one). It would be immensely helpful to be able to export/import groups between libraries the same way entries are, possibly within the same tool (i.e. with the option to choose which groups should be migrated and which shouldn’t, and the option to import all the groups that correspond to the imported entries).
Right now this can in part be done manually - one can copy the group list directly from one BibTex file to another. Unfortunately, this method doesn’t deal well with intersecting group lists. As an example, my main library might have papers on topics A and B, while my project specific library has papers on topics B and C. When I import the papers from my project library to my main library, I want to see the union of the two group lists, i.e. I want to be able to import the new group (C) without deleting my existing group (A)