Your "flow chart" is very confusing!
I have chosen the following procedure:
1. determine 2D rotation angle (angle in XY plane)
2. calculate 3D angle (angle in rotated XZ plane)
3. rotate original object around Y-axis with 3D-angle
4. rotate result of 3. around Z-axis with 2D-angle
5. move result of 4. to start and end point

@Allplan
The calculation of the 3D angle of a vector should be possible in a node!
AngleXZ and AngleYZ are not helpful for this often to be solved task!
Better would be to have an Node, which get a AxisPlacement3D from Vector,
and transform the objects with this AxisPlacement3D directly or via Matrix3D.
That nodes would havee a great benefit for all visual scripting users...