We propose a method for analyzing dynamic experiments done by means of surface force apparatuses on layers of end-grafted or adsorbed layers separated by a compatible polymer melt. We postulate a continuous variation of viscoelastic properties as a function of distance z to the plane. Focusing on small amplitude oscillations, the local behavior is described by a complex shear modulus G*(omega, z). In that context, we establish the solution of squeezing flow between plane and sphere. We apply it first to a five-layer configuration made of two layers stuck to the solid surfaces and an intermediate polymer melt separated from the layers by two connecting zones or interfaces. We discuss the results in the framework of tube models, including reptation and tube renewal. We compare them to the situation where the connecting zones are replaced by slipping planes. When the separation between the two surfaces is lower than the thickness of both layers, we solve Navier's equation for describing the compression of the inner part of the layers. The solution is compared to the static force profile obtained from static experiments. The overall complex modulus encompasses the viscoelastic behavior of both inner and outer parts of the gap and the elastic contribution of the inner part made of overlapped and tethered chains. Each part of the expression can be discriminated from the others, allowing experimentalists to play with the structural parameters of both free and tethered chains as well as with grafting density.