config files separation for each sites enabled

[Fred]

Hello freeradius-users,
I have 6 virtual servers on version 2.1.8, each listening on
differents ip addresses lo:[1-6].
I saw it was easy to separate clients files, using clients site-name
{} , and including a sitename.client.conf.
But as huntgroups and users files seems to be loaded globally before
sites instanciation, I found no way to dedicate  huntgroup and users
file to each server instance, as done previously for clients...
Is there any way to achieve this without having to launch many radiusd
in differents location ?

Best regards,
Fred MAISON