Anyone who thinks that you can be both trained in computer science and another engineering discipline in one undergraduate program clearly has no grasp of either field. Frankly, I do not think even a computing science B.Sc. They may know a lot of computing science, but they have little experience of how to apply that knowledge to serve the needs of clients as professionals. This is exactly like newly minted engineers, accountants, physicians and so on. If anything, software engineering should be a master's level discipline that requires substantial practical experience.
Software engineering belongs to no one discipline.
It is common to all disciplines that design and implement processes. But its notions of professional practice come from engineering. It affects the way organizations work, and whether they succeed or fail, and so it has aspects of business to it. Software affects people, and so it has aspects of psychology, anthropology, and sociology. It affects our rights, and so has aspects of law and political science.