cmake_minimum_required(VERSION 3.9)
project(foo)

set(CMAKE_CXX_STANDARD 14)
set(CMAKE_C_STANDARD  99)

add_subdirectory(lib/bar)
add_subdirectory(lib/baz)

cmake_minimum_required(VERSION 3.9)
project(bar)

add_library(bar SHARED a.cpp b.cpp)
set_target_properties(bar PROPERTIES VERSION ${PROJECT_VERSION})
target_include_directories(bar PUBLIC ${CMAKE_SOURCE_DIR}/lib/include)

cmake_minimum_required(VERSION 3.9)
project(baz)

add_dependencies(baz bar) #????
add_library(baz SHARED c.cpp d.cpp)
set_target_properties(baz PROPERTIES VERSION ${PROJECT_VERSION})
target_include_directories(baz PUBLIC ${CMAKE_SOURCE_DIR}/lib/include)