samba is running with SMBv2/SMBv3 protocols , so no more advertising through netbios which is deprecated for security reason (as is SMBv1).
you can install this contrib, still in smetest, to restore some advertising of the server.
https://wiki.contribs.org/WsddIt is working great, while some work still need to be done on it, but this is more in term of coding standard of the integration, nothing about its functionality.
Runlevel is a deprecated approach left with the end of SysVinit. We are using systemd, we then use target, and our target is sme-server.target. The philosophy of target is totally different of runlevel, so do not try to reproduce the behaviour, but rather try to integrate to the flow.
Systemd will launch in parallel all service that are able to be launched, while respecting their own dependencies. I.E. if service samba needs the network, it will wait for network to run before starting samba.
There is not real easy way to know the current target, while you can get what is the default target (which might not be the running target as one could have isolate to another one, or this one was not yet reached because it is waiting for a job to end ....
# systemctl get-default
sme-server.target
and check if some elements are still in queue before reaching the default target
# systemctl list-jobs
No jobs running.