The EOSC Interoperability Framework (EOSC IF) was mainly tailored from European Interoperability Framework (EIF) since (EIF) was not targeted at research communities. In order to promote interoperability within EOSC, the FAIR working group of the EOSC secretariat released a draft version of the EOSC interoperability framework. The draft version concentrated on data and related artifacts and did not cover legal interoperability issues. The updated version (link), includes the legal interoperability problems, needs and recommendations, as well as a reference architecture for the EOSC interoperability framework.
The EOSC IF is structured in a similar manner to EIF. More specifically, the EIF identifies four layers of interoperability (technical, semantic, organizational and legal), which have been also considered in the development of the EOSC IF (source: link).