  "A Three-Field Domain Decomposition Method" is the title of a seminal paper
by F. Brezzi and L. D. Marini which introduces a three-field formulation for
elliptic partial differential equations. Based on that, we propose the
Multiscale-Hybrid-Hybrid Method (MH$^2$M) for the Darcy model, a multiscale
finite element method that yields, after a series of formal manipulations, a
symmetric positive definite formulation that depends only on the trace of the
solution. We show stability and convergence results for a family of finite
element spaces and establish relationships with other multiscale finite element
methods.
