How to COMBINE the results of two nonlinear load cases?

Please referred to the attached model for more details

Basically I created two cables connected to a common joint.

The 1st load case is self-weight of the cables only.

The 2nd load case is a point load on the common joint.

Since the 2nd load case is followed by the 1st load case, so the result of 2nd load case includes the self-weight effect of the 1st load.

The X and Y displacements (ft) of the common joint under  two load cases are as follows:

1st load case:  X 0.0, Y -96.050

2nd load case: X -2.819, Y -114.506

Therefore, the X and Y displacemen due to point load ONLY is

X: -2.819-0=-2.819, Z: -114.506-(-96.050)=-18.456, this result matches that of Sap2000 verification problem.

As Technical Reference Manual says,

This command may be used to combine the results of the analysis. The structure will not be analyzed for the combined loading.

but there is no results in the load combination.

Please show me how to combine  the results of two nonlinear load cases?