Hello, Yukiya, and welcome to the Grammar Exchange.
Compound complex sentences are formed by two or more coordinate main clauses (with at least one of them containing a subordinate clause), for example:
- This is the reflection of who you are and this is the reflection of who you have become.
As you can see, both clauses can stand alone and are therefore two main clauses (in this case, with both of them containing a subordinate clause) joined by a coordinating conjunction -> compound complex sentence:
- This is the reflection of who you are.
- This is the reflection of who you have become.
In your sentence, you have two nominal relative (not just relative) clauses coordinated by "and," with both of them forming the object to the preposition "of" (I say they are "nominal relative" because the antecedent of "who" is found within the pronoun itself: who = the person that):
- This is the reflection of [who you are and who you have become despite all of those experiences] = This is the reflection of [the person you are and the person you have become despite all those experiences].
The sentence above is therefore only complex (the compound feature appears within the subordinate clause, not between two main clauses).