In to update link position within scene kindly follow the steps given below,
1. In Authoring section click onto the link of the scene.
2. As soon user clicks on link, button for "update position" appears on right hand as shown below,
3. Click on update position button and move the link over the scene to the required position.
4. Click the "complete" tab under Position section.Thus the position of the link gets updated to new required position.