I dont think naturally one person will have both Xi and Xe.
However I think you can develop some Xe-let's use Fe as an example, is you are an Xi-Fi user.
In this case for me, a mindest of compassionate detachment allows me to disconnect my Fi from my surroundings adn take on a more Fe feel. Is its Fe? Not like the Fe I felt when I cheated to get to Fe...that was living in another mind.
However it gives a surface veneer that appears Fe-like and enables me to function productively in an Fe dominant group.
I have been chatting with the entps about this as well-Ni/Ne and Ti/Te as well as Fi/Fe.
Jung proposed a "transcendant function" where the dominant function is balanced by development of the introverted aspect of it. Thus balance Ne with Ni? I dunno though...