I guess that you want contents of Koschei package groups to be populated with packages that are maintained by particular packager group in dist-git, is that correct?
If so then for each Koschei group I will need the name of corresponding dist-git group.
Do you want packages to be removed from Koschei group when they are no longer maintained by particular dist-git packager groups?
Also, I don't see "scitech_sig" global group in Koschei. If it doesn't exist then please create it first and point me to URL for that group.

Yes, that's correct. These are:

• neuro-sig in both: https://src.fedoraproject.org/group/neuro-sig and https://koschei.fedoraproject.org/groups/neuro-sig
• scitech_sig in both: https://src.fedoraproject.org/group/scitech_sig and https://koschei.fedoraproject.org/groups/ankursinha/scitech_sig

I just created the scitech_sig in Koschei, but it isnt in the list of "global groups". I hope that's OK.

Done. I've converted ankursinha/scitech_sig group to global group. Then I've set up both neuro-sig and scitech_sig groups as dynamic groups - every 3 hours group contents will be populated from set of packages maintained by corresponding dist-git group.

Thanks very much @mizdebsk ! That'll be really useful!