composer install from two composer.json file

I have multiple composer.json having multiple seperate dependency and want to install all the dependency in the both composer.json using single composer install command.

The location is like this:

| - composer.json
| - Custom
    | - Package1
        | - composer.json

First composer.json

{
    "name": "laravel/laravel",
    "description": "The Laravel Framework.",
    "keywords": ["framework", "laravel"],
    "license": "MIT",
    "type": "project",
    "require": {
        "php": ">=5.6.4",
        "barryvdh/laravel-debugbar": "^2.3",
        "laravel/framework": "5.4.*",
        "laravel/tinker": "~1.0",
        "laravelcollective/html": "^5.4.0"
    },
    "require-dev": {
        "fzaninotto/faker": "~1.4",
        "mockery/mockery": "0.9.*",
        "phpunit/phpunit": "~5.7",
        "symfony/css-selector": "3.1.*",
        "symfony/dom-crawler": "3.1.*"
    },
    "autoload": {
        "classmap": [
            "database"
        ],
        "psr-4": {
            "App\\": "app/",
        }
    },
    "autoload-dev": {
        "psr-4": {
          "Tests\\": "tests/"
        }
    },
    "scripts": {
        "post-root-package-install": [
            "php -r \"file_exists('.env') || copy('.env.example', '.env');\""
        ],
        "post-create-project-cmd": [
            "php artisan key:generate"
        ],
        "post-install-cmd": [
            "Illuminate\\Foundation\\ComposerScripts::postInstall",
            "php artisan optimize"
        ],
        "post-update-cmd": [
            "Illuminate\\Foundation\\ComposerScripts::postUpdate",
            "php artisan optimize"
        ]
    },
    "config": {
        "preferred-install": "dist",
        "sort-packages": true,
        "optimize-autoloader": true
    }
}

Second composer.json inside Package1 directory

{
    "name": "custom/package1",
    "description": "",
    "require": {
        "php": ">=5.6",
        "composer/installers": "~1.0",
        "lavary/laravel-menu": "1.7.1"
    },
    "autoload": {
        "psr-4": {
            "Custom\\Package1\\": ""
        }
    }
}

I want to install the lavary/laravel-menu inside the Package1 to the main vendor directory where all the default packages are installed.

|- vendor  //<==want here
| - composer.json
    | - Custom
        | - Package1
            | - vendor  //<== not here
            | - composer.json

I have tested this solution:

http://ift.tt/2xTHWR6

like this:

{
    "config": {
        "vendor-dir": "../../vendor/"
    }
}

This installs the packages but we need to get into the second composer.json instead of main composer.json and removes the installed package from first composer.json.

How can i install the all the dependency from the main composer.json without getting into the second or multiple composer.json in single vendor directory?

via Chebli Mohamed