Autocomplete from all files in project

I have the following scenario in javascript (nodejs).

Function a exports an object which consists of other functions. The output of function a is passed as parameter to function b. As I use the parameter a in function b there is no intellisense whatsoever. What I am asking is how to enable intellisense from all files in the project if even possible. There is such thing by default in WebStorm and Atom and it's really helpful. Otherwise, intellisense when modules are directly required is flawless.

I'm completely aware of the built in intellisense. After having a 3rd look at the intellisense docs still cant seem to figure out my issue. If I have done a bad job explaining what's wrong please let me know.

via Biser Atanasov