On pp. 147-148 of his study entitled The Early History of Heaven--J. Edward Wright associates the Test. of Levi and 2 Cor. 12:1-4:
"The Greek text [of Levi] did not evolve from a three-heaven to a seven-heaven schema as Charles, Bitenhard, and Kee assume. The shorter versions are a corruption of an earlier seven-heaven schema. It is very posible that a later Christian hand revised the original seven-heaven schema to a three-heaven schema in light of the Apostle Paul's ascent to the 'third heaven.'"
James M. Scott (2 Corinthians in the New International Biblical Commentary series) states:
"Although Jewish and Christian apocalypses often presuppose a cosmology of seven heavens (cf. A.Y. Collins), some texts do speak of three heavens, the third of which is the highest, the dwelling place of God himself (cf. 1 En. 14:8-25; T. Levi 3:4)" (p. 224).