This barely qualifies as an answer in its own right: the method is the same as @quellenform's, [here][1] The only difference in this answer, is that the sorting method is packed into a group for re-use, and the choice of weight by which to sort.

This group, given a weight, will capture the sorted indices of points on the points themselves:

[![enter image description here][2]][2]

It creates a dummy Curve Line with the same number of points as the incoming geometry, for the sole purpose of using Curve Topology's *Points of Curve* node, which, given weights, can return sorted indices. It transfers the weights from the incoming geometry to the curve by index,  returns the sorted indices back to the incoming geometry's points (by index), and captures them.

The group can be used to sort set of points; here, clockwise, by feeding it [1- a *Radial* texture] as the weight:

[![enter image description here][3]][3]

Transforming the point-cluster on the left to the point-cluster on the right:

[![enter image description here][4]][4]

Point 0 could be moved around by rotating the texture, or adding to the sorted index, modulo (point-count)

[<img src="https://blend-exchange.com/embedImage.png?bid=EAV7A5jb" />](https://blend-exchange.com/b/EAV7A5jb/)




  [1]: https://blender.stackexchange.com/a/277587/35559
  [2]: https://i.sstatic.net/VaPaA.png
  [3]: https://i.sstatic.net/EroED.png
  [4]: https://i.sstatic.net/tM2Di.png