Hey there, welcome to the site!

The general rule is, if you were aware that you were dreaming, then it was a lucid - congrats!! I don't think it really matter whether you were in a dream of a dream or not -- it was still a dream and you were aware of it. At least, that's my take on it.

In fact, I had a brief LD last night in one of those "second level" dreams (that's my term for them). I had been trying to fall back asleep for so long after a WBTB that when I eventually fell asleep I dreamed of trying to fall asleep. Finally I found myself lying in bed on my stomach, and could feel that I was asleep and dreaming, so I "got up" (carefully so as not to disturb myself ), and found that when I walked out of my bedroom I entered another place entirely, and was able to fly, etc. But I woke up quite soon afterward, to find myself sleeping on my back in real life -- in other words, I awoke directly from the "second level" to reality. A dream is a dream is a dream.