Mixing microphase-separating diblock copolymers and nanoparticles can lead to the self-assembly of organic/ inorganic hybrid materials that are spatially organized on the nanometer scale. Controlling particle location and patterns within the polymeric matrix domains remains, however, an unmet need. Computer simulation of such systems constitutes an interesting challenge since an appropriate technique would require the capturing of both the formation of the diblock mesophases and the copolymer-particle and particle-particle interactions, which can affect the ultimate structure of the material. In this paper we discuss the application of dissipative particle dynamics (DPD) to the study of the distribution of nanoparticles in lamellar and hexagonal diblock copolymer matrices. The DPD parameters of the systems were calculated according to a multiscale modeling approach, i.e., from lower scale (atomistic) simulations. The results show that the positioning and ordering of the nanoparticles depend on several different factors, including their covering type and volume fraction. Also, the geometric features of the matrix are found to exert an influence on the particle location and pattern. The overall results provide molecular-level information for the rational, a priori design of new polymer-particle nanocomposites with ad hoc, tailored properties.