This is a simple Python3 script that parses a list of SPEC files and generates a nice graph of the dependencies among them using DOT.
pip3 install rpm-spec-dependency-analyzer
rpm_spec_dependency_analyzer --output reqgraph.dot /my/spec/folder/*.spec
dot -Tpng reqgraph.dot -o reqgraph.png
This is the example of the graph generated by pkgA.spec and by pkgB.spec:
Original .dot source is available here