Explain me how libraries are searched in this case - c++

Question

Simplified a little
I have a project with 2 targets (subdirectories): first libMain.so library, who linked with second libDependent.so :
add_library( Main SHARED ${cpp} )
target_link_libraries(Main
Dependent
)
I make a conan package, that contains 2 libraries - libMain.so and libDependent.so inside /package/CONANPACKAGEID/lib folder
In conan also located FindMainPackage.cmake with example code
find_library (Main_LIBRARIES Main Main_d
HINTS ${Main_ROOT_DIR} ${CMAKE_INSTALL_PREFIX}
PATH_SUFFIXES lib
)
and find_path
In my general project I use find_package(Main) and link my third lib with Main
target_link_libraries(General
${Main_LIBRARIES}
)
or
target_link_libraries(General
Main
)
both variants are work
And last I linked this lib with my google test binary
target_link_libraries( Test
GTest::GTest
General
)
If I set to LD_LIBRARY_PATH a variable ${CONAN_LIB_DIRS_MAIN} (equal /package/CONANPACKAGEID/lib) and run binary from build dir from terminal -> it work good, all libs are found
But if I try to run w/o (5) I get the output
error while loading shared libraries: libDependent.so: cannot open shared object file: No such file or directory
I check my binary with ld command and get the output
libMain.so /.conan/data/package/CONANPACKAGEID/lib/libMain.so (0x00007c815718f000)
libDependent.so => **not found**
If I link my General with Dependent
target_link_libraries(General
Main
Dependent
)
all works good and libDependent.so located in conan package near with libMain.so in ld output
My questions:
Why my binary know thatlibMain.so inside conan package folder. This conan package are not exists in lib pathes ( check with ldconfig)
Why my binary cannot find libDependent.so automatically
How I can fix this or how work with situation right?
Thank you for help, my brain in over after 2days...