user group allowed just a specific device.

Hello all. I'm running a FreeRADIUS which search user groups on the LDAP and permid or denny the access. Every think works fine but now I'm needing a new kind of restriction. There is a user group that they just can access some specific defice. So what I want is put this configuration to work. What I think: Is this configuration is possible? Is this configuration is made on user file? Today my enviroment is working but the user group has access on all device. If I put the this new group, ou users, on the same where is working they will have access to all equipament and this is not what is needed. Bast regards. -- Atenciosamente, Kalil de A. Carvalho