You can try following steps:

• get points from the polylines with the node "GetPolyPointCurvePoints"
  
• get x,y and z coordinates from points with the node "Point3DDeconstruct"
  
• write them to a table with the node "WriteCSV".
  

The coordinates which gets written will be always in mm by default, because it is the internal unit used by Allplan. If you want to have the number in different unit, you may need to convert by yourself first.