The easiest way is just to parent the black objects to the red object, that way their rotation will be relative to the red object. If they are all USceneComponents you can just use AttachTo. Otherwise, you’ll need to write some code that grabs the parent transform, and then applies the local child transform.
Hmm, I assume these vectors aren’t actual objects? I.e. they don’t have full transforms? They’re simply a bunch of vectors? 2D/3D (although that shouldn’t really matter)?