Neural networks modularity is a major challenge for the development of control circuits of neural activity. Under physiological limitations, the accessible regions for external stimulation are possibly different from the functionally relevant ones, requiring complex indirect control designs. Moreover, control over one region might affect activity of other downstream networks, once sparse connections exist. We address these questions by developing a hybrid device of a cortical culture functionally integrated with a biomimetic hardware neural network. This design enables the study of modular networks controllability, while connectivity is well-defined and key features of cortical networks are accessible. Using a closed-loop control to monitor the activity of the coupled hybrid, we show that both modules are congruently modified, in the macroscopic as well as the microscopic activity levels. Control impacts efficiently the activity on both sides whether the control circuit is an indirect series one, or implemented independently only on one of the modules. Hence, these results present global functional impacts of a local control intervention. Overall, this strategy provides an experimental access to the controllability of neural activity irregularities, when embedded in a modular organization.