Level 3
This level will provide you with basic problem solving skills like conflict resolution and restoring files from history. Without this knowledge, it's only a matter of time until you run into trouble.
Here's the cheat sheet for level 3. You may also want to revise the level 2 cheat sheet.
Undo and redo the last operation on the repository
jj undo
jj redo
Track a remote bookmark in order to push to it
jj bookmark track <NAME>@origin
Delete a commit (and bookmarks pointing to it)
jj abandon <CHANGE_ID>
Restore the state (of a specific file) (from a specific commit)
jj restore [--from <CHANGE_ID>] [FILE_TO_RESTORE]
Split a messy working copy
jj commit --interactive