Model-Based Engineering (MBE) and Product Line Engineering (PLE) have been combined, to handle new system development constraints like: increasing complexity, higher product quality and cost reduction. Many authors have pointed out the need of modularization in the variability and in the core assets space. Existing approaches focus on separating and delimiting concerns or providing generic composition mechanisms. In Model-Based Product Lines, with an increasing number of models to manage, organizing the modeling space becomes central to support product line consistency, maintenance and product derivation process. To organize the modeling space, we propose to precisely describe the dependencies among modeling artifacts and clarify their use. Thus, we introduce the Product Line Modeling Space (PLiMoS) language that specializes relationships, based on an intentional framework, for the product line domain. The Domain Specific Language (DSL) provides a solution to model the modeling space and preserves independence with the product line tooling.