just wanna know how is Jenkinsfile used among multiple branches in a company , single Jenkinsfile for multiple branches with conditionals or any other way or plugins? i dont mind using multiple jenkinsfile but implementing it and merge would cause a overwrite i think

I have 3 main, dev , release and a feature branch which should be triggered based on pull-requests to dev.

pipeline {
agent any

environment {
    BRANCH_NAME = env.BRANCH_NAME ?: 'unknown'
    CHANGE_ID = env.CHANGE_ID ?: ''
}

stages {
    stage('Initialize') {
        steps {
            echo "Building branch: ${BRANCH_NAME}"
            echo "Pull Request ID: ${CHANGE_ID}"
        }
    }

    stage('Build') {
        when {
            anyOf {
                branch 'main'
                branch 'dev'
                expression { return env.CHANGE_ID != '' } // For pull requests
            }
        }
        steps {
            script {
                if (BRANCH_NAME == 'main') {
                    echo "Building main branch"
                    // Main branch-specific build steps
                    sh 'echo Main branch build process'
                } else if (BRANCH_NAME == 'dev') {
                    echo "Building dev branch"
                    // Dev branch-specific build steps
                    sh 'echo Dev branch build process'
                } else if (env.CHANGE_ID != '') {
                    echo "Building feature branch for PR to dev"
                    // Feature branch-specific build steps
                    sh 'echo Feature branch build process'
                }
            }
        }
    }

    stage('Test') {
        when {
            anyOf {
                branch 'main'
                branch 'dev'
                expression { return env.CHANGE_ID != '' } // For pull requests
            }
        }
        steps {
            script {
                if (BRANCH_NAME == 'main') {
                    echo "Testing main branch"
                    // Main branch-specific test steps
                    sh 'echo Main branch testing process'
                } else if (BRANCH_NAME == 'dev') {
                    echo "Testing dev branch"
                    // Dev branch-specific test steps
                    sh 'echo Dev branch testing process'
                } else if (env.CHANGE_ID != '') {
                    echo "Testing feature branch for PR to dev"
                    // Feature branch-specific test steps
                    sh 'echo Feature branch testing process'
                }
            }
        }
    }

    stage('Deploy') {
        when {
            anyOf {
                branch 'main'
                branch 'dev'
                expression { return env.CHANGE_ID != '' } // For pull requests
            }
        }
        steps {
            script {
                if (BRANCH_NAME == 'main') {
                    echo "Deploying main branch"
                    // Main branch-specific deployment steps
                    sh 'echo Main branch deployment process'
                } else if (BRANCH_NAME == 'dev') {
                    echo "Deploying dev branch"
                    // Dev branch-specific deployment steps
                    sh 'echo Dev branch deployment process'
                } else if (env.CHANGE_ID != '') {
                    echo "Deploying feature branch for PR to dev"
                    // Feature branch-specific deployment steps
                    sh 'echo Feature branch deployment process'
                }
            }
        }
    }
}

post {
    always {
        echo 'Cleaning up...'
        // Clean up actions, e.g., deleting temporary files
    }
    success {
        echo 'Pipeline succeeded!'
    }
    failure {
        echo 'Pipeline failed!'
    }
}

}