Random splines for a road tracks or braided streams ?

Does anyone  know  right way  or could point me to a relevant tutorial?  I need not a tree like "splines on a spline"  but rather  vertical splines  with random subtle  waviness    getting random x and y shift  . 

  Is there something like index parameter   in spline nodes  like inside fx map node ?    A way to  set spline quadratic  node spline amount to say 10  and  use each spline index  to give each its own subtle  random points  wavines .     A super easy to do thing in Blender geometry nodes  with clear and easy preview  but I broke my mind alredy trying to do it in Designer. 

I see I can do  10  pre-made  splines manually   with some functions controlling  points position  for each of them individually ,   map a texture on splines,  and then feed each one to fxmap node  to shift in 0-1 space. Is it  only way?

I mean in Blender I can use line primitives  with arbitrary number of point  always distributed  proportionally , resample  curve  node and so on and on.      Maybe  someone have and can share   such line primitive done for designer  ?