I would like to expand on the answer provided by David Vogt and supported by BillJ in the comments. The word both is often the first part of a two-part conjunction, called correlative conjunction. Correlative conjunctions are, for instance, both...and, either...or, neither...nor, etc. Correlative conjunctions exist in many languages. Often both parts have the same form, such as et...et 'both...and' in French.
The question is directed at the difficulties associated with parsing coordinate structures involving correlative conjunctions and more generally. Indeed, theories of coordination abound, and therefore the associated parse trees also vary a lot. Some approaches try to integrate coordination into the greater theoretical apparatus used for subordination, whereas other approaches see coordination as a structural phenomenon that is distinct from subordination in major ways. The great variation in accounts bears witness to the difficulties posed to theories of syntax by coordination.
The reason I am expounding on the challenges presented to syntactic theory by coordination is that whatever parse tree is produced for the example (i.e. It is evident for both you and the listener), many experts will not agree. I think all one can expect in this area is that whatever analysis one opts for, one can also support this analysis in some way.
In the dependency grammar (DG) I prefer, I would produce the following parse tree of the example sentence:
This analysis views coordination as fundamentally distinct from subordination, as indicated by the presence of the long horizontal bracket connecting the coordinated expressions you and the listener. The words both and and enjoy a special status as coordinators; they are linked directly to the word that immediately follows and serve as markers of the start of the initial and final conjuncts. I expend a lot of energy motivating this type of approach to coordination in Chapters 10 and 11 of this book: https://benjamins.com/catalog/z.224.
The first part of a correlative conjunction typically appears at the left periphery of the coordinate structure. There are, however, many cases where it appears further to the left where one might not expect it to appear because it no longer marks the start of the coordinate structure. Compare the following pairs of sentences:
(1) a. Frank has purchased either [cigarettes] or [chewing tobacco].
(1) b. Frank has either purchased [cigarettes] or [chewing tobacco].
(2) a. It is evident for both [you] and [the listener].
(2) b. It is evident both for [you] and [the listener].
The square brackets mark the conjuncts of the coordinate structure each time. Examples (1b) and (2b) demonstrate that there is flexibility concerning the placement of the initial correlative coordinator; it can also appear further to the left. In such cases, I prefer to view it as an adverb or particle of a sort, that is, it no longer serves to mark the start of the initial conjunct. I would parse sentence (2b) as follows:
To summarize, parsing sentences containing correlative elements such as both is difficult, mainly because of the challenges posed by coordination to syntactic theory in general. Furthermore, correlative conjunctions themselves pose additional challenges. Much is open to debate.
