multiple sub projects in a workspace

Question

I have been working this way in several other environments like Android and Java on the server side, and we call it multi-modular project, but I'm finding it hard to implement it in XCode for iOS Projects.

The idea is to break a project into smaller sub-projects, each sub-project possibly having its own storyboard, its own classes and struct having an implicit namespace.

Base project will be single view application with a target, here's what the structure looks like.

Workspace

    - BaseApp (having a target and Single View Application with a storyboard)
    - ModuleA (having a storyboard)
    - ModuleB (having a storyboard)

1. BaseApp can load/unload or mount/unmount storyboards of ModuleA and ModuleB.

2. ModuleA or ModuleB can be any type of projects.

I did some attempts using storyboard references from the baseapp and try to load storyboards in ModuleA or ModuleB but its unable to find its reference.

Wondering how a Multi-Modular project is implemented in XCode?