How to setup a multi root git project?

Hello, I am trying to setup a project as following:

Lets assume that there is a WebApp-1, it relies on Framework-1 as well as other Modules, like Module-1

1) WebApp-1

2) Framework-1

3) Module-1

Now I want Framework-1 to be the main git repository for the framework and each part of that framework to be its own module and have its own git repository

Example project structure:

Framework-1.git -> has Directory Modules -> has directory "Framework-Module-1" -> has content of Framework-Module-1.git
Framework-1.git -> has Directory Modules -> has directory "Framework-Module-2" -> has content of Framework-Module-2.git
Framework-1.git -> has Directory Modules -> has directory "Framework-Module-3" -> has content of Framework-Module-3.git

Now when I check out Framework-1 into Project WebApp-1, I would obviously need all files from the framework and all its modules available. 

Example:
WebApp-1.git -> Directory Framework -> has content of Framework-1.git (Including content of all modules, eg sub git remotes)

So far I've went thru: https://www.jetbrains.com/help/phpstorm/git-branches-in-multirooted-projects.html

And what I can accomplish is:
Project Framework-1 -> has Directory Modules -> has directory "Framework-Module-1" -> has content of Framework-Module-1.git
Project Framework-1 -> has Directory Modules -> has directory "Framework-Module-2" -> has content of Framework-Module-2.git
Project Framework-1 -> has Directory Modules -> has directory "Framework-Module-3" -> has content of Framework-Module-3.git

But the Framework-1 git doesn't know anything about the modules git repositories, so when I check out Framework-1, the modules are missing.

Then I added the directory of each framework-module to VCS, then pushed. After that I can see in the git log that each framework-module directory refers to the corresponding git repo, however yet again when I checkout Framework-1, the sub directories for all the modules are empty. (eg. no pull from framework-modules git repos) 

Can this be accomplished?