This sample file demonstrates how you can use the Join Paths node combined with a repeated freeform path segment to create symmetrical guilloche/spirograph style continuous paths.
To add further variation to the path a Modify Path node is then used to add an additional transformation, scaling every eighth control point in this new joined path in to change very other fold in the curve.
You can find out more details about this technique in this video: https://youtu.be/o6ofvka6Czk