title: How to access jenkins parent job build id in a MultiJob?
body: <p>I have a requirement to trigger Automation Suite in multiple phases and summarize test results in a single test summary report.</p>
  
  <p>I configured a Jenkins Multi Job to trigger my automation suite, which is divided in to multiple chunks say suite#1, suite#2, suite#3, suite#4 (each suite is a maven job) into 2 phases. </p>
  
  <p>Phase#1 is a multi job having suite#1, suite#2 run in parallel and Phase#2 is another multi job having suite#3 and suite#4. While phases run in sequential.</p>
  
  <p>I have trouble getting the parent build id, in my suite#1 job. This is needed for linking back the results to parent. </p>
  
  <p>Eg: Parent Job - Build number is PB_001, 
        assigned into a custom variable myBuildNumber=PB_$BUILD_NUMBER
      Phase# 1:
           Suite#1 build number 101
           Suite#1 build number 201
      Phase# 2:
           Suite#1 build number 301
           Suite#1 build number 401</p>
  
  <p>When ever I try to access myBuildNumber it is giving the current job Build number i.e as PB_101 rather than the one preserved in Parent job.</p>
  
  <p>Please suggest if this can be achievable or not? I tried using Parameter Plugin/Pre Defined parameters still i couldn't get parent Build number.</p>
  
  <p>Thanks you</p>