Cmake project with nested directories

CMakeLists.txt

cmake_minimum_required(VERSION 3.9)
project(CMake_With_Makefile)

#========== Global Configurations =============#
#----------------------------------------------#

set(CMAKE_CXX_STANDARD 17)     
set(CMAKE_VERBOSE_MAKEFILE ON)

function(ADD_RUN_TARGET tname target)
    add_custom_target( ${tname}
        COMMAND ${target}
        DEPENDS ${target}
        WORKING_DIRECTORY ${CMAKE_PROJECT_DIR}
    )
endfunction()

    #=============================================#
    #  T A R G E T S  C O N F I G U R A T I O N   #  
    #=============================================#


add_subdirectory(lib_util)
add_subdirectory(lib_tool)

       add_executable( app1 app1.cpp )
target_link_libraries( app1 lib::util lib::tool )

if(UNIX)
    # Set RPATH in the executable for making it relocatable on Unix.
    # It allows installing the application on any directory or 
    # running the application from any directory without 
    # 'symbol not found or library not found' errros. 
    set_target_properties( app1 PROPERTIES INSTALL_RPATH "$ORIGIN/../lib")                       
endif()

       add_executable( app2 app2.cpp )
target_link_libraries( app2 lib::util lib::tool)
# set_target_properties( app2 PROPERTIES INSTALL_RPATH "$ORIGIN/../lib")                       


ADD_RUN_TARGET(run-app1 app1)
ADD_RUN_TARGET(run-app2 app2)

    #===========================================#
    #  I N S T A L  L    T A R G E T            #
    #===========================================#


install( TARGETS  app1 app2 util tool 
         RUNTIME  DESTINATION bin   # Executables and DLLs (Windows Only)
         LIBRARY  DESTINATION lib64 # Shared libraries: *.so or *.dylib 
         ARCHIVE  DESTINATION lib64 # Static libraries: *.a 
)

install(FILES LICENSE.txt DESTINATION data)