Here's my interpretation of what Nunes is saying:
The communications of Americans being picked up while monitoring foreigners is legal and routine. No big deal there, and if some of those Americans are Trump and his people, still no big deal. The issue is what the intelligence organizations do with the intercepted American communications. Apparently they are supposed to redact all names (unless necessary to understand context) and in general avoid focusing on them. In this case, what Nunes is suggesting is that not only were the names not redacted but disseminated, and the Trump people became the focus of reports based on these communications, which were then widely circulated in the intelligence community because of Obama's executive order on 12333 data collection being shared by all intelligence agencies which intern, allows more people have access to leak the communications. Trump will probably use this as validation on his claims that "Obama tapped his phones".
Needless to say, I'm not vouching for the validity or significance of Nunes' claims. But this appears to be what he's saying, IMO. What it boils down to is the Trump WH is pissed that all their communications with Russia got leaked.