Okay, In the rules book it says that if you are locked in adjacent to a hovering figure that the hovering figure can attack or be attacked with a ranged combat move....

fine but if I have a hovering character say Thanos and someone brings a Shield Agent adjacent to me can I attack a character other than the shield agent using my ranged combat...? also if I choose can I use a multiple ranged combat attack at that point?

thanks

When adjacent to an opponent's figure, you can only attack those adjacent figures.
A flyer can multi-target range attack all adjacent enemies.
A grounded figure can multi-target range attack all adjacent enemies if all enemies are flyers.

In your scenario, Thanos can only attack the Shield agent.

The only character you can attack is the one adjacent to the hovering figure, so no multiple ranged attacks are allowed.