I would like to retrieve some of them in one of my queries.
Though, when constructing a collection object query, I am unable to specify species taxonomic rank and still select these fields. The only options are Author, Full Name and ID.
As you mentioned, in the next Specify release, we are expanding the query builder’s capabilities to allow searching on the “Group Number” field at any rank, but not on every field. The issue requesting this functionality to be expanded to all fields (#4697) is still open, though I do wish for this functionality to be added as soon as possible.
I’ve added your request to the issue to emphasize the importance of resolving this! I have also forwarded this suggestion to the developers for consideration in a future release.