Loops through jobs by regex printing the job name and the value of the parameter PARAM1

jenkinsGetJobParameters.groovy

import jenkins.model.*

def matchedJobs = Jenkins.instance.items.findAll { job ->
    job.name =~ /job_regex_here/
}

matchedJobs.each { job ->
  def latest = job.getLastSuccessfulBuild()
  def name = job.name
  
  // resolve the parameter
  def param1 = latest.buildVariableResolver.resolve("PARAM1")
  println "${name}:${param1}"
}