There used to be a tool in InRoads (I think it was part of the Generate Longitudinal Feature) where you could project the slope between 2 elements onto a third element. The is no such tool in ORD.

The only way I can figure to do it now is to create a template with three points, and have the third point be a vector offset of the first two points. Then create a corridor on one of your elements using this template, point control the second point vertically and horizontally to your second element, and point control your third point horizontally to the element you want the profile for. Then if you don't want the corridor sticking around, you would need to copy the new profile in place to drop it as just graphics so you can delete the corridor that was only being used to get this profile. Then apply a feature definition to the new profile and set it as active.

This seems like a whole lot of work to do something you used to be able to do with one tool and a couple clicks. It would be great to have that tool back (or something similar as I assume this would be a profiling tool now instead of creating a 3D element like it used to.

See attachment for an illustration of what I am referring to. In the attachment, I would be projecting the slope between elements A and B onto a third element C. The slope between elements A and B can be continually changing and none of the elements need to be perpendicular. If it were a constant slope or consistently changing slope you could just use Profile By Slope From Element, but in my case, I don't know the slope because it is continually changing.