I asked the following question on Stack Overflow:
I'm using Jenkins with a branch parameter to specify the branch to build from. Other stuff downstream needs the branch name to not have the leading "origin/" -- just "feature/blahblah" or "bugfix/12345" or similar. The advanced settings for the parameter let me specify a branch filter via regex, but I'm a regex newbie and the solutions I've found in searching are language-dependent. The Jenkins documentation for this is sparse.
When a user clicks on "build with parameters", for the branch I want to see branch names that omit the leading "origin/". I'm not sure how to write a regex for Jenkins that will "consume" that part of the branch name before setting the parameter value.
I solved this problem once before, I'm pretty sure using Stack Overflow, but I can't find those hints now.
I got an answer that uses a Groovy script, which depends on adding a plugin. I decided to wait a few days before exploring adding plugins to our server.
In the meantime I figured it out and added this answer:
For the git branch parameter, set Branch Filter to:
I found the parentheses to be counter-intuitive, because if you don't specify a filter you get:
(No parens.) If you are filtering stuff out, you use parens to indicate the part to keep.
I have a lot to learn about regex patterns, it appears.