I would like to remove the wall line below the beam.

[LeeJaeYoung]

Green is visible.
The black hidden lines are the walls of the lower layer.
However, I want to make the black line under the beam invisible.
What do other people do?
SOE also didn't help.
And this beam is LB1 beam, which indicates the lintel above the opening.

[martin-b]

Maybe I don't really understand what you are trying to model, but can't you make the opening as an empty door opening? There you can set the contour line for the opening as dashed or dashdot. If you need the lintel in the 3D, you can still add it above your empty opening.