CMAKE: How do I install executable along with required dylib to custom directory?

So I'm using CMake to build a C++ project (on Mac OS) and my project relies on a dylib (I'm using TBB https://www.threadingbuildingblocks.org/ but the specific library itself doesn't matter)

If I do a standard "cmake" and "make" it builds the executable where I want it and when I run my app, the dylib links correctly and everything works perfectly.

The problem comes in when I try to do a "make install" and try to run the resulting executable from the install directory. I get an "image not found" error:

dyld: Library not loaded: @rpath/libtbb.dylib
Referenced from: 
/Users/MyName/Desktop/ProjectRoot/install/./MyApp
Reason: image not found

Interestingly, if I do a regular "make" without an install, and then manually copy over the executable to the install directory, then that will link against my dylib properly. I have no idea why that is.

My directory structure is as follows:

Root 
    CMakeLists.txt 
    Source/ 
    Libraries/ 
        tbb/ 
            include/ 
            lib/ 
                libtbb.dylib
    install/ 

...and my CMakeLists.txt file is below:

# Start of CMakeLists.txt
cmake_minimum_required(VERSION 3.3)
project (MyApp)

# Set C++ version and output paths
set (CMAKE_CXX_STANDARD 14)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_SOURCE_DIR})
set(CMAKE_MACOSX_RPATH 1)
set(CMAKE_INSTALL_PREFIX "${CMAKE_SOURCE_DIR}/install")
set(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/lib")

# Find TBB
find_library (
    TBB_LIBRARIES
    NAMES tbb libtbb # what to look for
    HINTS "${CMAKE_SOURCE_DIR}/Libraries/tbb/lib" # where to look
    NO_DEFAULT_PATH # do not search system default paths
)

# Set Custom Include Files + TBB header files 
include_directories(Source/Headers Libraries/tbb/include)


# Set Source Files
file(GLOB_RECURSE SRC_FILES "Source/*.cpp")
add_executable(MyApp ${SRC_FILES})

# Link Libraries 
target_link_libraries(MyApp ${TBB_LIBRARIES})

# Set compile flags
set_target_properties(MyApp PROPERTIES CXX_STANDARD 14) #LINK_FLAGS "-Wl")
target_compile_features(MyApp PUBLIC cxx_std_14)

# Install executable
install(TARGETS MyApp DESTINATION .)

If I try to also add the following line, and install the dylib as well:

install(TARGETS ${TBB_LIBRARIES} DESTINATION lib)

then when I do a "make install" I get the following error instead:

install TARGETS given target 
"/Users/MyName/Desktop/ProjectRoot/Libraries/tbb/lib/libtbb.dylib"
which does not exist in this directory.

So I just can't seem to get this install to work. How do I fix it so that both my executable and my library get installed in the right place and that my executable will be able to link against my library when run?