Well from what I've learned through sources,etc
the 7 heavens are the levels of Jannah,and in the 7 heavens,there is an area which has a kaaba-like structur and what exceeds beyond that, at the end of The 7 heavens or above the 7 heavens is the lote tree,or sidrat al muntaha, where Muhammad SAW met Allah in Isra'a wal Miraaj