How to write a dynamic declarative pipeline that contains sequential job inside parallel job - jenkins-pipeline

Question

I'm trying to write a declarative pipeline code that accepts a map and create a pipeline. I can able to achieve sequential stages or parallel stages but facing problems while making a pipeline that contains sequential stages inside parallel stages.
The input data would be Map. Each list in the map should run parallel and the items inside the list corresponding to each key should run in sequentially.
example data : [1:[11,12], 2:[21,22], 3:[31,32]]
The output should be of image. Could someone give some idea?
Below is the code i have tried.
def stageData = [1:[11,12], 2:[21,22], 3:[31,32]];
def getDeployStages1(stageData){
Map deployStages = [:]
stageData.each{ key, stgValue ->
List stgs = []
stgValue.each{ value ->
deployStages.put("${value}", {
echo "${value}"
})
}
}
return deployStages;
}
def getDeployStages2(stageData){
Map deployStages = [:]
stageData.each{ key, stgValue ->
List stgs = []
stgValue.each{ value ->
stgs.add(stage("${value}"){
echo "${value}"
})
}
deployStages.put("${key}", stgs)
}
return deployStages;
}
pipeline {
agent any
stages {
stage ("deploy1") {
steps {
script {
parallel getDeployStages1(stageData)
}
}
}
stage ("deploy2") {
steps {
script {
parallel getDeployStages2(stageData)
}
}
}
}
}

Answer 1

According to this documentation you can nest the stages in this way
pipeline {
agent none
stages {
stage("build and deploy on Windows and Linux") {
parallel {
stage("windows") {
agent {
label "windows"
}
stages {
stage("build") {
steps {
bat "run-build.bat"
}
}
stage("deploy") {
when {
branch "master"
}
steps {
bat "run-deploy.bat"
}
}
}
}
stage("linux") {
agent {
label "linux"
}
stages {
stage("build") {
steps {
sh "./run-build.sh"
}
}
stage("deploy") {
when {
branch "master"
}
steps {
sh "./run-deploy.sh"
}
}
}
}
}
}
}
}
This should result in the following flow
To apply this in your case, you can simplify your functions to return just elements that need to be sequential (just the values).
pipeline {
agent any
stages {
stage ("parallel") {
parallel {
stage ("deploy1") {
stages {
def list = getDeployStages1(stageData)
for (int i=0; i < list.size(); i++) {
stage(i) {
echo("${list[i]}")
}
}
}
stage ("deploy2") {
stages {
//similar
}
}
}
}
}