Not necessarily filesystem paths (in my case, the paths correspond to RocksDB keys). And I’d like to be able to fold/unfold subtrees, search within node names,

Not necessarily filesystem paths (in my case, the paths correspond to RocksDB keys). And I’d like to be able to fold/unfold subtrees, search within node names, and call arbitrary commands for a given path in the tree, from within a TUI. So no, `tree` won’t cut it.