I'm not sure what you are asking. Nagios is not going to show you anything that you don't tell it. It is not a DISCOVERY tool.
I have switchA connected to switchB via port 1 on each switch.
But I don't tell nagios that switchA is the parent host for switchB, so when I look at the status map on my nagios website, it looks to me that A and B are not even connected to each other. But is that really how my network is setup? No it isn't, but that's how I told nagios it was setup.
I've posted extensive, and exaustive topics on this subject and I'm not going to repeat it. Use the search and a sticky on the top has some pointers.
Nagios' status map is ONLY as GOOD and ACCURATE as you TELL it to be. The status map will reflect what you have defined in your HOSTS.cfg file.