pipeline
{
    agent none
    stages
    {
        stage('s1') {
            matrix {
                axes {
                    axis {
                        name 'axis'
                        values 'axis1', 'axis2', 'axis3'
                    }
                }
                stages {
                    stage('s2') {
                        when {
                            beforeAgent true
                            expression { axis != 'axis2' }
                        }
                        agent none
                        steps {
                            print axis
                        }
                    }
                }
            }
        }
    }
}