If something is "under one's nose," it means that it is happening or located very close by, but the person is unaware of it. Some synonyms for this phrase include "in plain sight," "within reach," "at arm's length," "in close proximity," or "just around the corner." Other useful phrases that convey a similar meaning include "right under one's nose," "within sight but out of mind," or "hiding in plain sight." All of these phrases suggest that something is nearby, but the person is either not paying attention, or simply unaware of what's happening right under their nose.
