The tree view provides a raw view on your LDAP directory. This feature is for people who are experienced with LDAP and need special functionality which the LAM account modules not provide. E.g. if you want to add a special object class to an account or edit attributes ignoring LAM's syntax checks.
To use this tool you will need to configure its suffix in your LAM server profile on first tab. You can also specify multiple suffixes separated by semicolon.