Is there a way to modularize Jenkinsfile while keeping the stage functionality?

I have a enormous Jenkinsfile that I need to modularize to improve maintainability, so what I want to do is seperate build, test and deploy into individual files but each has multiple stages and I don't want to lose the functionality to display each stage on Jenkins and check their errors easily.

Example:

 stages {
        stage('Clone') {}
        stage('Pre Build Clean') {}
        stage('Copy Requirements') {}
        stage('Build') {}
        }

I want to move all of this into build.groovy and call it by

stage('Build') {
    steps {
        script {
            build.buildApp()
        }
    }
}

at the same time maintaining the stage view on Jenkins. Is this possible or is there a better way to do this?

You can reach this by hosting the stages code in an external file.

// build.groovy


def buildStages() {
    return [
        stage('Build 1') {
            // Do not use steps directive here
            // This code will be imported in a steps block (inside Jenkinsfile)
            println 'Build 1'
        },
        stage('Build 2') {
            println 'Build 2'
        },
    ]
}

return this

You can invoke then the added function in the Jenkinsfile

pipeline {
    agent any
    stages {
        stage('Import lib'){
            steps {
                script {
                    buildLib = load 'build.groovy'
                }
            }
        }
        stage('Build') {
            steps {
                script {
                    buildLib.buildStages()
                }
            }
        }
    }
}

Note that a parent stage will be added. It might not suit your need of maintaining the stage view. The stages view will look like