Hmm not sure what you’re trying to do, but to mix animations together and blend them, you can use Animation Montage,
there you also set the SlotName (for example UpperBody), so that in CharAnimation Blueprint you can set up a node UpperBody that will affect only upper body, this way you can have for example base animations that drive your character and at certain events you can override animations on UpperBody part only.
Nice example tutorial : - YouTube