Using a Jenkins pipeline to checkout multiple git repos into same job

Here's Mine

    stage('CheckoutModule1') {
        steps {
            sh 'mkdir -p Module1'
            dir("Module1")
            {
                git branch: "develop",
                credentialsId: 'aaa',
                url: '[email protected]:b/module1.git'
            }
        }
    }

    stage('CheckoutModule2') {
        steps {
            sh 'mkdir -p Module2'
            dir("Module2")
            {
                git branch: "develop",
                credentialsId: 'aaa',
                url: '[email protected]:b/module2.git'
            }
        }
    }

You can checkout those three git repositories into three subdirectories by using the checkout SCM step three times like this:

stage('Checkout') {
 // Get CalibrationResults from GitHub
 checkout([  
            $class: 'GitSCM', 
            branches: [[name: 'refs/heads/master']], 
            doGenerateSubmoduleConfigurations: false, 
            extensions: [[$class: 'RelativeTargetDirectory', relativeTargetDir: 'CalibrationResults']], 
            submoduleCfg: [], 
            userRemoteConfigs: [[credentialsId: '6463627-ab54-4e42-bc29-123458', url: 'https://github.com/AtlasBID/CalibrationResults.git']]
        ])
 // Get Combination from GitHub
 checkout([  
            $class: 'GitSCM', 
            branches: [[name: 'refs/heads/master']], 
            doGenerateSubmoduleConfigurations: false, 
            extensions: [[$class: 'RelativeTargetDirectory', relativeTargetDir: 'Combination']], 
            submoduleCfg: [], 
            userRemoteConfigs: [[credentialsId: '6463627-ab54-4e42-bc29-123458', url: 'https://github.com/AtlasBID/Combination.git']]
        ])
 // Get CombinationBuilder from GitHub
 checkout([  
            $class: 'GitSCM', 
            branches: [[name: 'refs/heads/master']], 
            doGenerateSubmoduleConfigurations: false, 
            extensions: [[$class: 'RelativeTargetDirectory', relativeTargetDir: 'CombinationBuilder']], 
            submoduleCfg: [], 
            userRemoteConfigs: [[credentialsId: '6463627-ab54-4e42-bc29-123458', url: 'https://github.com/AtlasBID/CombinationBuilder.git']]
        ])

}

You can use the dir command to execute a pipeline step in a subdirectory:

node('ATLAS && Linux') {
    dir('CalibrationResults') {
        git url: 'https://github.com/AtlasBID/CalibrationResults.git'
    }
    dir('Combination') {
        git url: 'https://github.com/AtlasBID/Combination.git'
    }
    dir('CombinationBuilder') {
        git url: 'https://github.com/AtlasBID/CombinationBuilder.git'
    }

    sh('ls')
    sh('. CombinationBuilder/build.sh')
}

If your repository has submodules use git checkout

pipeline {
agent {label 'master'}
stages{
    stage("Demo"){
        steps{

            echo 'Hello World'
        }
    }
    stage("Source"){
        parallel{
            stage('CalibrationResults'){
                steps{
                    echo 'Checking out CalibrationResults'
                    checkout([$class: 'GitSCM', branches: [[name: '*/CI-CD-Demo']], doGenerateSubmoduleConfigurations: false, extensions: [[$class: 'CloneOption', depth: 0, noTags: true, reference: '', shallow: false, timeout: 60], [$class: 'SubmoduleOption', disableSubmodules: false, parentCredentials: false, recursiveSubmodules: true, reference: '', timeout: 60, trackingSubmodules: true], [$class: 'RelativeTargetDirectory', relativeTargetDir: 'server-core'],[$class: 'CheckoutOption', timeout: 60]], submoduleCfg: [], userRemoteConfigs: [[url: 'https://github.com/AtlasBID/CalibrationResults.git']]])
                }
            }
            stage('Combination'){

                steps{
                    echo 'Checking out server spoke'
                    checkout([$class: 'GitSCM', branches: [[name: '*/master']], doGenerateSubmoduleConfigurations: false, extensions: [[$class: 'CloneOption', depth: 0, noTags: true, reference: '', shallow: false, timeout: 60], [$class: 'SubmoduleOption', disableSubmodules: false, parentCredentials: false, recursiveSubmodules: true, reference: '', timeout: 60, trackingSubmodules: true], [$class: 'RelativeTargetDirectory', relativeTargetDir: 'server-spoke'], [$class: 'CheckoutOption', timeout: 60]], submoduleCfg: [], userRemoteConfigs: [[url: 'https://github.com/AtlasBID/CombinationBuilder.git']]])


                }
            }
        }

    }

}
}

Generated using Checkout git snippet generator