I am trying to create a Jenkins job that has dependent parameters.
Firstly I want to be able to choose a main parameter: 
And then secondly to be able to choose from a set of options that are dependent parameters of the main parameter. 
If I select a different main parameter: 
I then want to have a different set of options as the dependencies to the second main parameter. 
Please, can you help me with how I can achieve this?
I would suggest the Active Choices plugin (also known as "uno-choice"). (This question has references to both, though they're not the accepted answer.)
For your specific use case, you'll want to add two parameters to your job:
Active Choices Parameter
Script: Groovy Script
return ['A','B'] Active Choices Reactive Parameter
Script: Groovy Script
def choices switch(MainOption){ case 'A': choices = ['Blue','Green','Yellow'] break case 'B': choices = ['Black','White','Grey'] break default: choices = ['N/A'] break } return choices Fallback Script: Groovy Script
return ['Option error'] Referenced parameters:
MainOption The "Referenced parameters" setting is the key - when that value is changed, the plugin will re-evaluate the Groovy script, giving you the dependent parameter effect.
For all of you who stumble upon the same kind of problem (like I did). There is a fairly new Jenkins plugin available that does exactly what is desired here: display a dependent set of drop-downs, updating dependent boxes when a main box changes selection.
For your job you just need to follow the following steps:
The "multiselect parameter plugin" can be installed from Jenkins plugin management, the documentation is available on its Jenkins Plugin page.
H,Main option,Dependent option V,SELECTED_MAIN,SELECTED_DEPENDENT C,A,Blue C,A,Green C,A,Yellow C,B,Black C,B,White C,B,Grey When you run "build with parameters" in your job, the following boxes are displayed for selection:
In your build script you can simply use the configured environment variables SELECTED_MAIN and SELECTED_DEPENDENT, which contain the selected values from both select boxes.
