Ahh right, with the drag style input. It should still work if you clamp it.
If you did it this way, you would add a Float Clamp on the axis you want to clamp, just after you Get Axis, use Float Clamp on the result. Float Clamp would come from a variable, when the character gets to the edge of the screen have a trigger send a change to that variable that Float Clamp is using, also revert it when they exit the trigger.
The order of actions is what is important in the movement FSM, it needs to get the raw input information and store it, then you have to clamp it to something else. So if the player hits the edge of the screen the clamp number changes. If you aren't at the edge of the screen then it would just be something like -50.0 to 50.0 so it isn't clamping anything, but once the trigger hits and it changes the clamp value in the Movement FSM it will be -1.0 to 0.0 which would change the input value and stop the ship from moving in some direction.