An expanding balloon is the standard picture/analogy to elucidate the expanding universe. OK, let's go with that; an analogy ostensibly represents an ANALOG to the subject, right?
The balloon is a 2-D surface, but in 3-D space, there's a center. Inhabitants of Balloon World are stuck within that surface. They cannot point toward the center, but we can see it.
Now, extend to our universe, expanding space, yadada. By analogy - remember that one? - there must be a point in some 4-D space, surrounding us, which constitutes the center. So, the question is, can we 'point' to it, through some 4-D mathematical abstraction, derived from our measurements?