Regarding the original question - perhaps you are simply looking for:
Also, if you ever need to convert from world → local (or the other way round), there’s a bunch of nodes that handle that:
There are equivalent nodes for direction and rotation, and entire transforms even. And matrices, too - if you ever need to deal with scale, for example.
There’s a lot hidden in the tooltips:
Some tooltips have more info:
Although, how it works and what info is provided is somewhat inconsistent throughout the engine.