How does VSE's "Change Effect Input" work?

This question may be a bit basic, but I can’t figure it out and Googhle is no help.
I have a transform effect strip which is not straightforward to recreate. Then I realize it should take different strip as input. How can I do that? There is a “Change Effect Input” submenu under C, which contains three entries “A -> B”, “B -> C” and “A -> C”. None of these seem to do anything.

If you mean that you want to recreate the effect of a transform strip by copying both the input strips and the transform strip, then that’s doable by choosing the third option “change path/files”. In the new window that will open just select the new input (image or video) for the first input strip and repeat for the second. That way you’ll be able to recreate the transform with new inputs. Great time saver btw.

Path/Files is greyed out when Transform strip is selected. And I don’t want to copy input strips, I just want the Transform strip (or its copy) to use another input from what it was created for.

You can target another source strip with shift key and do a swap function.

Check out an old tutorial I made (for color correction) at 3min 50sec aprox I run through duplicating and retargeting an effect strip.

That worked, thanks.

@3pointEdit Thank you! Your video just saved me too.
How did you ever figure that out to begin with?
There is a drop-down box that’s totally empty so you can’t select a source, and you can’t paste a strip name into it either.
I’ve got to think this is an unfinished UI element they’re planning to complete at some point in the future? :rolleyes:

It is actually a left over from blender 2.4 days, the VSE had a more fully implemented plugging system that required this sort of function. It has since been mostly replaced by modifiers.