Exactly.
The important thing for me—and this is what we mean by “functional bilingualism”—is that you have sufficient command of both languages to do the job. It is always measured functionally, that is, in the context of the task to be done.
In my opinion, a high degree of skill in both languages is required. I have described to you a little bit of what is involved. You have to read complex texts. You have to interact with very intelligent people in another language, which requires advanced skill in both languages.