Hi,
They are having same address family " Inet labeled-unicast".
By mentioning "rib inet.3" you are isntructing which table the labeled route should be installed.
Also, rib-group is telling what are the tables that the routes should be installed.
I am not sure that you can use rib-groups with other side rib inet.3 to make this work,
You need to check the routing and the labels whether they are having correct entries.
Regards,
Moses N