The software FEATFLOW, mainly developed at TU Dortmund, is a powerful CFD (Computational Fluid Dynamics) tool and a central part of the StroemungsRaum platform, which has been successfully used in an industrial environment for years by IANUS Simulation. Here, algebraic three-level domain decomposition methods are further developed for use in FEATFLOW and optimized for solving CFD problems with a view towards Exascale computing. The new methods are implemented in the software package FROSch, a Trilinos-based open-source implementation of linear Schwarz methods, and integrated through an interface in FEATFLOW and StroemungsRaum. We take an algebraic approach to simplify the integration.