There are no path objects in construct. You can 'fake it' by placing objects as 'marks', and moving your followers from marker to marker.
Using commands like qarp and cubic, you can smooth the movement between points so objects travel along a curve. Unfortunately, it's difficult to visualize this in the editor, which severely limits how practical this approach is in a real game, especially if you have multiple paths.
One place where it might be practical is for a racing game, as there would only be one path, and you would have a visual representation courtesy of your track itself. You could possibly use the 'car' behavior and simply turn toward a point; the physics built into the behavior should smooth the movement from point to point into a curve.
Here is a crude implement of my own, made for a different purpose, using the qarp command to control movement between points.
https://www.dropbox.com/s/cv2gume289gl2 ... .capx?dl=0
One day, hopefully, we'll get a proper path tool.