If memory serves me, I’ve seen these forms around and supposedly they mean the same thing - “I’ve been doing”. If that’s true, would one be preferred over the other in certain situations?
Se a memória não me falha, já vi essas formas e supostamente significam a mesma coisa - “I’ve been doing”. Se estivesse correcto, será que um deles se preferia a algum outro em certas situações?
Olá. They all would have the same English translation, yes. In terms of the nuances between them in Portuguese, I can say the following, not as fixed grammatical rules, but conclusions from average patterns of use:
Tenho feito (and tenho andado a fazer, not mentioned by you) would normally refer to something you’ve been doing for a more prolonged period of time, i.e. not just the same day or the day before, but the last week, month, year or beyond, as informed by context. For example, we might ask “O que é que tens feito nestes últimos anos?” (What have you been up to these last few years?) to an acquaintance we haven’t seen for a couple years.
Ando a fazer and tenho estado a fazer allow references to both the immediate past and a slightly more prolonged one, but not as prolonged as the previous options can be. These are always preferably shorter-term phrases. For example, a parent might walk up to their child’s room and ask “O que é que andas/tens estado a fazer?” in reference to the last few hours only.