[BUG] Forked sessions aren't grouped in the session picker

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

According to the official docs on claude --resume,

Forked sessions created with /branch, /rewind, or --fork-session are grouped under their root session. Press → to expand a group.

This doesn't work for me on the latest version of Claude Code (2.1.212). If I create branched sessions and try resuming them, they'll show up in the session picker. But there isn't any grouping or hierarchy to show that they're actually branches.

What Should Happen?

When resuming via /resume or claude --resume, forked sessions should be grouped under the root session.

Error Messages/Logs

Steps to Reproduce

1. Open Claude and give it any prompt. This is the root session.
2. Create a branch with /branch and give it any prompt.
3. Go back to the CLI and type claude --resume. Both sessions should appear in the list, but ungrouped:

test branch 5 minutes ago · main · 18.7KB Root session 5 minutes · main · 13.8KB

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.212 (Claude Code)

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

WSL (Windows Subsystem for Linux)

Additional Information

_No response_