ERL_LIBS can simply point to the parent directory where all your dependencies projects reside. If your projects follow the Erlang Project directory convention ( yourproject/src, yourproject/ebin, yourproject/include ) then Erlang will dynamically associate the ebin and include from those projects to your context.
Example
/place/Project1
/place/Project1/ebin/...
/place/Project1/include/...
/place/Project1/deps/...
/place/Project1/deps/DependencyProject2...
/place/Project1/deps/DependencyProject3...
As it canbe seen above, /place/Project1/deps is the container for other sub-projects ( dependencies ). In this case if you can run your application as
erl env ERL_LIBS "/place:/place/Project1/deps". This will include all related projects ( Project1, DependencyProject2 and DependencyProject3 ) in your runtime context.