You can specify the scope of a search as one-level or subtree.
You can specify the following search scope to search for entries from the LDAP directory server:
One-level
When you specify one-level, the search is restricted to the immediate children of a base object, but excludes the base object. You can use one-level to perform a search for immediate child objects of a parent object.
For example, consider a parent object P1 and its immediate children C1, C2, and C3. When you specify one-level, the search evaluates C1, C2, and C3 against the search criteria, but does not evaluate P1. Use a one-level search to include all children of an object.
Subtree
A subtree search returns all child objects that are subordinate to the base object including the base object.