This is a collection of some modified hair node groups which come with Blender.
The interpolate curves node supports parting by texture: https://www.youtube.com/watch?v=9x0TxfFsk6Q&t=35s
The clump hair node supports twisting: https://www.youtube.com/watch?v=L_YcxO_U5yg&t=489s
The create guide index node support input of custom guides: https://www.youtube.com/watch?v=sgC8Sp_jFj4&t=121s
The blend hair node supports a group Index