I'd like devise a two dimensional differential system that blends two stable centers, centered at arbitrary coordinates, using as few variables as possible. This means that the differential system contains two equilibrium points that can be locally approximated as a stable center, and otherwise, the unique trajectories smoothly deform from one stable center to another as you move between them.
As an example, the following
$x' = -(y-a)(y-b), y' = (x-a)(x-b)$
blends two arbitrary stable centers together centered at $(a,a)$ and $(b,b)$, but it is difficult to extrapolate how to center these at $(a,c)$ and $(b,d)$.