I would translate this specific part of the phrase as followed: "multifaceted and dynamic" = "متنوعون وديناميكيون"

However, the translation of the phrase where this expression is included would be as followed:
“the beauty of men and women is that they are multifaceted and dynamic, but what unifies them is the confidence in being who they are."
=
".جمال الرجال والنساء هو أنهم متنوعون وديناميكيون لكن ما يوحدهم هو الثقة بأن يكونوا كما هم"

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Note added at 2 hrs (2023-04-19 22:34:16 GMT)
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I would improve the phrase translation with a little polishing by modify it as followed:
"جمال الرجال والنساء هو أنهم متنوعون وديناميكيون لكن ما يوحدهم هو الثقة بأن يكونوا هم أنفسهم"
I believe this option better emphasizes individuality and uniqueness and it captures the essence of the original English part of phrase "in being who they are."

Note! The translation "multifaceted and dynamic" = "متنوعون وديناميكيون" is steady and I stand for it.