The CenA/M83 group is a nearby dense complex (~4Mpc) dominated by a giant elliptical and a giant spiral, hosting more than 60 dwarf companions with a variety of morphological types and stellar contents. My aim is to constrain galaxy evolution processes through the study of resolved stellar populations of galaxies in this group. Firstly, for dwarf members I characterize the recent star formation histories and metallicity content (by using optical and near-infrared data from ACS/HST and ISAAC/VLT), and compare them to what is known for Local Group dwarfs, underlining similarities and differences. My results probe the fundamental interplay between nature (mass) and nurture (environmental effects) in shaping the evolution of dwarfs in groups of galaxies. I furthermore present results from the first deep survey of resolved stellar populations in the remote outer halo of our nearest giant elliptical, CenA (VIMOS/VLT optical data). Tracing its halo structure (radial profile, extent and metallicity) out to a remarkable ~14 Reff and comparing the halo stellar populations to those of CenA's dwarf companions enables me for the first time to constrain the mechanisms that contributed to the build-up of CenA in the context of cosmological galaxy formation models.