Creating a curve path for gameObject which reacts to Triggers

I am trying to create a path for a gameObject which will bounce off other gameObjects if it hits them. Can I get an idea on how I could possibly get this curve path set up.

Stuck on ideas. I don’t want to use ITween and I can’t simply define the entire path via ITween either. I need to account for whether it hit another gameObject and cause it to carry on the path or just fall through.

Attached the image below for clarification. I need the circle(purple) gameObject to bounce along the white path provided the rectangle(green) gameObject is in place to cause a Trigger and let the path carry on or the circle gameObject just simply falls through.

There is only 1 green gameObject at any point of time which moves to one of the 3 possible positions. Placed 2 just for clarification.

I have uplaoded a zip file here http://wikisend.com/download/608526/BezierCurve.rar.
Unzip it , drag the BezierCurve Prefab in your Scene and you can adjust its handles to get the desired curve.

While doing so , make sure you have Gizmo unchecked in the Scene and Game View else you will have difficulties in viewing the curve.

Once that is done , you can visit here 4. Tweening Along a Path or Spline · prime31/GoKit Wiki · GitHub and Make your GO follow the spline.