The educational governance discourse aims at capturing how different actors, participating in a specific political process, coordinate their actions while working together within multi-actor policy networks. In Germany, such multi-actor policy networks have set up ambitious political goals on the implementation of education for sustainable development (ESD) that has resulted in the National Action Plan. The current domestic slogan “From Project to Structure” reveals the overall aim of scaling ESD. In this article, a governance perspective is used to examine how the actors involved in ESD in Germany coordinate their actions with each other. Six focus group discussions for different educational areas were conducted and analyzed with a structuring content analysis in MAXQDA. Additionally, an in-depth case comparison of the actors from different sectors (administration, politics, academia, civil society, and educational practice) was carried out. The results show sector-specific boundary work—the way in which actors construe, maintain, or even bridge boundaries when coordinating their actions in scaling ESD. Actors from the various sectors positioned themselves in patterns of more structure-immanent or more structure-transcending positionings. The conclusion shows that reflection and relational agency is pivotal for cooperation within multi-stakeholder governance networks and for moving strategically within structures.