In the following example
If I hadn't have been too nice, I would still have my wallet.
is past past perfect a possible structure? If so, shouldn't it be "hadn't had been"?
In the following example
If I hadn't have been too nice, I would still have my wallet.
is past past perfect a possible structure? If so, shouldn't it be "hadn't had been"?
I guess that you are thinking about backshifting because you are using a hypothetical conditional.
Here is a summary of the backshifting rules: note that past perfect backshifts to... past perfect, so there is no need for a past past perfect. The correct sentence is therefore
If I hadn't been too nice, I would still have my wallet.
In his description of time and tense in English, McCawley argues that multiple levels of perfects are indeed possible. Since some perfects are logically past tenses embedded within past tenses, we get past within a past within a past ... as a consequence of embedding past tense clauses within past tense clauses. The argument is given on page 225 of The Syntactic Phenomena of English. However, McCawley proposes, since the morphological system of English does not allow multiple perfects in the auxiliaries of a single surface clause, all but one perfect "have" markers are deleted.