CMakeLists install library without dependency headers

Question

I'm trying to set up the build process of my library using cmake's install/export, for which the built lib and header files will be packaged up as a .deb using dpkg-buildpackage. I was trying to follow the guide on https://cmake.org/cmake/help/git-stage/guide/importing-exporting/index.html for the most part, so as to make my package findable after install using find_package.

The issue I'm facing is when my libraries have nested dependencies from my other folders/projects, which I add using add_subdirectory().

My main CMake for the project I want to build/export is

cmake_minimum_required(VERSION 3.10)
project(exampleLib)

add_subdirectory(../path/to/dependencyA ${PROJECT_BINARY_DIR}/dependencyA)

include(GNUInstallDirs)

add_library(exampleLib SHARED
    exampleLib.cpp
)

target_link_libraries(exampleLib PRIVATE
    dependencyA
)

target_include_directories(dashStreamerClient PUBLIC
    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
    $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
)

# dependencyA has a dependency on "dependencyB"
# which if I don't include here, errors with 'CMake Error: install(EXPORT "exampleLibTargets" ...) includes target "dependencyA" which requires target "dependencyB" that is not in any export set.'
install(TARGETS exampleLib dependencyA dependencyB
        EXPORT exampleLibTargets
        LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
        ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
        RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
        INCLUDES DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
)

# Note: I only want this exampleLib.h file to be "installed" in CMAKE_INSTALL_INCLUDEDIR, not any of the other dependencies headers as they are unnecessary!
install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/exampleLib.h DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
install(EXPORT exampleLibTargets
        FILE exampleLibTargets.cmake
        DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/exampleLib
)
# Make a package configuration file
include(CMakePackageConfigHelpers)
# Config.cmake.in copied from the importing-exporting cmake guide
configure_package_config_file(${CMAKE_CURRENT_SOURCE_DIR}/cmake/Config.cmake.in
  "${CMAKE_CURRENT_BINARY_DIR}/exampleLibConfig.cmake"
  INSTALL_DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/exampleLib
)
install(FILES
          "${CMAKE_CURRENT_BINARY_DIR}/exampleLibConfig.cmake"
          "${CMAKE_CURRENT_BINARY_DIR}/exampleLibConfigVersion.cmake"
        DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/exampleLib
)
export(EXPORT exampleLibTargets
       FILE "${CMAKE_CURRENT_BINARY_DIR}/cmake/exampleLibTargets.cmake"
)

while my dependencyA's CMakeLists.txt is

cmake_minimum_required(VERSION 3.10)
project(dependencyA)

add_subdirectory(path/to/dependencyB ${PROJECT_BINARY_DIR}/dependencyB)

add_library(dependencyA SHARED
    dependencyA.cpp
)

target_link_libraries(dependencyA PUBLIC
    dependencyB
)

target_include_directories(dependencyA PUBLIC
    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
)

The issue is when I try to make install, I get the error

CMake Error at cmake_install.cmake:152 (file):
  file INSTALL cannot find
  "/home/me/path/to/exampleLib/include/dependencyB.h":
  No such file or directory.

where CMake tries to find the header of the nested dependencyB inside my current CMake project's path, but dependencyB.h is actually in e.g. path/to/dependencyB which was defined in the add_subdirectory of dependencyA. I also do not actually want this dependencyB.h to be installed, as it is not necessary, and only want exampleLib.h.

What am I doing wrong?

Thank you!