They are the latter two of those targeting Carter Page and (by extension) the Trump campaign. One of those was applied for by the Mueller Special Counsel. It's likely the cause of this admission is the Kevin Clinesmith faked emails
The first two FISAs on Carter Page are still being looked into.
This should, logically, mean everything they found based on that information is fruit of the poisoned tree and inadmissible. But it's not clear they found anything from that warrant that was useful in criminal court. It was political intelligence they were after. If Mueller used it even just to generate leads to look into things (like the Cohen situation), that could rapidly run into problems. But we just don't know what role -- including an intermediate role without being directly submitted to a court -- the information collected from those wiretaps played in later prosecutions. DOJ will be looking into that.
There's potentially a lot of fallout here since it imperils the entire existence
of the Mueller special counsel investigation, if that was predicated on anything found in the wiretaps.