Just wanted to asked everyone's though about this, because I am unsure myself.
Let's say that I have an Upsilon Shuttle, with Hux (crew) and advanced sensor. If I elect to use advance sensor and use coordinate, and use Hux, can I do the multiple coordination?

Relevant wording is :
Advanced Sensor - After you reveal your dial, you may perform an action. You cannot perform another action during this activation.
General Hux - if you do a White COORDINATE action you can treat it as Red. If you do, you may coordinate two additional ship.

in that case, is the mention of ''you may coordinate two additional ship'' telling you to do 2 extra coordinate action, and thus would be stopped by advanced sensors, or is the 3 instance of coordinate one single action.

I personally think it is the later, but I wanted to check what people thought.

General Hugs works with Advanced Sensors.

Here's the key: they spell out the word "coordinate" rather than having the symbol with the [three chevrons/ships in formation]. Similar language has been seen before where a ship might be instructed to--with the word rather than the symbol--boost with the word (such as Decloak or Tractor Beam) or acquire a lock. These are different from the "Lock Action" or "Boost Action" which will always be denoted by the symbol.

Here's the relevant rule (Action, p. 3): Game effects such as “gain 1 focus token,” “boost,” or “acquire a lock” are not actions, and a ship can resolve these game effects any number of times each round. Game effects such as “perform a [Focus] action,” “perform a [Boost] action,” or “perform a [Lock] action” are actions, and therefore each ship can perform each of these actions only once per round.

Coordinate isn't on that list, but neither is barrel roll or evade. The context is clear, however. The word "coordinate" and the action [Coordinate symbol] are distinct. The action is once-per-turn, but the game effect is distinct.

(Coordinate, p.8): Pilots can coordinate to assist their allies. When a ship performs the [Coordinate Symbol] action, it coordinates. A coordinating ship is a ship that is attempting to coordinate by performing the following steps:

1. Measure range from the coordinating ship to any friendly ships.
2. Choose another friendly ship at range 1–2.
3. The chosen ship performs one action.