Mac path to the GlobalDefines.xml file:
/Users/[your_user_name_here]/Library/Application Support/Steam/steamapps/common/Sid Meier's Civilization V/Civilization V.app/Contents/Home/Assets/Gameplay/XML/GlobalDefines.xml
Mac path to the .dylib files:
/Users/[your_user_name_here]/Library/Application Support/Steam/steamapps/common/Sid Meier's Civilization V/Civilization V.app/Contents
There are 3 .dylib files which I think correspond with the core game, G&K expansion, and BNW expansion:
libCvGameCoreDLL_DLL.dylib
libCvGameCoreDLL_Expansion1_DLL.dylib
libCvGameCoreDLL_Expansion2_DLL.dylib
Link to the core .dylib file here:
https://www.dropbox.com/s/xqb2o4qv9xrsmjt/libCvGameCoreDLL_DLL.dylib?dl=0