pipeline {
    agent any
    environment {
        LEVAR1 = "LE VALUE 1"
    }
    stages {
        stage('Example') {
            environment {
                LEVAR1 = "LE NEW VALUE"
                LEVAR2 = "A COPY OF ${env.LEVAR1} in build#${currentBuild.number}"
            }
            steps {
                echo "LEVAR1 ${env.LEVAR1}"
                echo "LEVAR2 ${env.LEVAR2}"
            }
        }
    }
}