How can I create a group that includes only “parent” entries? That is, I need to include the entries used in @incollection, @inproceedings, etc. via xref/crossref fields.
Matteo
Unfortunately, I don’t think it is currently possible to add entries based on “entrytype” to groups via automation.
The only way is to search for @incollection (or any other entrytype you want to include in your group), then select all entries and add them manually to a group.
I would suggest to open an issue on github to “add entries to groups based on entrytype”.
Did you try to to configure the group sourch with following
entrytype=patent
I found the expression via https://docs.jabref.org/finding-sorting-and-cleaning-entries/search#advanced
Does that solve the issue?