i have a hidden temporal breach on battlefield with my nasus. opponent plays charm to move my nasus. i play the hidden temporal breach to target my nasus. will the charm still move my nasus?

Yes — Charm fizzles and Nasus stays put.

Your hidden Temporal Breach has Reaction (assuming it was hidden on an earlier turn), so you play it in response to Charm, targeting Nasus at the battlefield where it was hidden — legal, since Hidden only restricts targets to that battlefield. Breach banishes Nasus and its owner replays him to the same location as a brand-new game object, so Charm's target has changed zones to and from a non-board zone and is no longer legal. Charm resolves with no effect: nothing moves (Rule 359.3.e.4).

Two small notes: Nasus comes back exhausted, but he's still there so you keep the battlefield. And you must fire the Breach while Charm is on the chain — if you let Charm resolve first, you lose the unit and the cleanup that follows trashes the hidden card. (If that's Nasus, Ascended, Charm's caster also has to pay 2 extra any-domain power for Deflect 2 just to target him.)