CMAKE_PARENT_LIST_FILE
From Get docs
Cmake/docs/3.21/variable/cmake parent list file
CMAKE_PARENT_LIST_FILE
Full path to the CMake file that included the current one.
While processing a CMake file loaded by include() or find_package() this variable contains the full path to the file including it. The top of the include stack is always the CMakeLists.txt
for the current directory. See also CMAKE_CURRENT_LIST_FILE.
© 2000–2021 Kitware, Inc. and Contributors
Licensed under the BSD 3-clause License.
https://cmake.org/cmake/help/v3.21/variable/CMAKE_PARENT_LIST_FILE.html