Remember/keep multiple branches uncollapsed

[smccants]

It would be a useful enhancement to keep a section uncollapsed after a user has opened it, even if they open a different part of the tree.
For example:

The user has unfolded "Backups". The user then clicks to unfold "Networking" and the "Backups" section refolds up in current behavior. I'd like the option to keep "Backups" open, allowing the user to see down multiple branches at once, if the user so chooses.