Hello and welcome to blenderartists !
Currently no, however you can always look here : Let's regroup Geometry Nodes Groups - Resources and Links
I still think that in the long run maybe it’s best to wait for the extension platform to eventually support nodegroups. I don’t know if it’s planned but since it’s supports themes nodegroups and materials seems to naturally fit.
The only downside is that it’s likely to take some time , for now having a thread like the one I posted could be a good start at least !