This is helpful if you want JobA to run x times, depending on/using users's input during runtime, or some other use case.
1) Create a Variable object (I'm using a Static Variable in this example)
2) Create a Promptset with Checklist. Make sure that you check "Array" under Multi-select.
3) Create a job or script that will use the value passed
4) Create a ForEach workflow. Add the Promptset that you created and the job. In the ForEach tab, enter the variable name of the Checklist in your Promptset.
5) Execute the workflow. Select values from the Checklist. Notice it will loop through all the values you selected.