node('linux'){
    echo "${env.PATH}"
    echo "${env.JAVA_HOME}"
    echo "${env.PATHEXT}"
}
node('windows'){
    echo "${env.PATH}"
    echo "${env.JAVA_HOME}"
    echo "${env.PATHEXT}"
}

Started by user FirstName LastName
[Pipeline] node
Running on linux.example.local in /var/lib/jenkins/workspace/jenkins-bug
[Pipeline] {
[Pipeline] echo
/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin
[Pipeline] echo
null
[Pipeline] echo
null
[Pipeline] }
[Pipeline] // node
[Pipeline] node
Running on windows.example.local in c:\Users\jenkins\workdir\workspace\jenkins-bug
[Pipeline] {
[Pipeline] echo
/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin
[Pipeline] echo
"C:\Program Files\Java\jdk1.8.0_112"
[Pipeline] echo
.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC
[Pipeline] }
[Pipeline] // node
[Pipeline] End of Pipeline
Finished: SUCCESS