Creating a new ticket as suggested in JENKINS-50164:

Using Jenkins v 2.121.3 I see that the help text in the Home directory section of the /configure page is still refleting that the workspace location can be set in the "Advanced" section".

This almost lead me to file a bug as it was something that was possible earlier and this was still being reflected in the embedded documentation (hence my expectation of it should still be possible).

Searching for the bug here let me see that it's a "feature" no longer being able to configure this in the UI )

Suggestion:

Make the UI help text reflect where to set this, EG by a link to this page https://wiki.jenkins.io/display/JENKINS/Features+controlled+by+system+properties
or by making a reference to the config.xml file in the Jenkins installation dir.

...Under the Advanced section, you can choose to store build workspaces and build records elsewhere.