Is it within a behavioral neurologists scope treat primary psychiatric disorders such as bipolar along w/ psych symptoms from neuro conditions?

Yes: As a clinical psychiatrist I can attest to this; Neurologists prescribe many of the medications that psychiatrists use, frequently ‘off label ‘ and because off-label prescribing is less well-established and using medications requires dose titrations that someone prescribing the medication regularly ‘on label’ , neurologists likely know how to dose these meds better than us psychiatrists.

Yes: A behavioral psychologist would have the range of knowledge to treat coexisting bipolar unless verbalized preference for a psychiatrist to handle that