JabRef supports grouping of entries.

1. Open https://github.com/JabRef/jabref-demonstration-libraries/blob/main/chocolate/Chocolate.bib in JabRef
2. Go to Richard_2017
3. Go to tab "General"
4. Enter "demo" in "Keywords". See the special ediutor (2 in screenshot)
5. Add ", Paywalled" in "Groups". See no special editor. (1 in screenshot)

Task:

1. Rename org.jabref.gui.fieldeditors.GroupEditor to org.jabref.gui.fieldeditors.GroupsEditor (with s) - to have consistent name with KeywordsEditor
2. Make an abstract superclass "TagsEditor", where KeywordsEditor and GroupsEditor inherit
3. Make GroupsEditor supporting tags (where the tags are groups)

Links (background):

• Initial support for TagsField for keywords: Implemented TagsField for the Keywords field #10910
• Improvement wish: Improve TagsField of keywords #10984