groupField names the field to group by. It is the only line to change when you want a different grouping.

Two nested lists do the work:

• f.valuesAll collects each distinct value of that field, sorted
• f.tiddlersFor returns the tiddlers holding one of those values

This test case imports 24 bibliography tiddlers from the GroupedLists/Bibliography payload. They came from a BibTeX import, so the field is bibtex-author rather than author.

Barker and Shang each published twice, so their groups list two titles. Set groupField to bibtex-entry-type to regroup the same data by publication type.