LdapGroupsMapping has lots of configurable properties and is thus fairly complex in nature. HDFS Permissions Guide has a minimal introduction to LdapGroupsMapping, with reference to "More information on configuring the group mapping service is available in the Javadocs."
However, its Javadoc provides no information about how to configure it. Core-default.xml has descriptions for each property, but still lacks a comprehensive tutorial. Without a tutorial/guide, these configurable properties would be buried under the sea of properties.
Both Cloudera and HortonWorks has some information regarding LDAP group mapping:
But neither cover all configurable features, such as using SSL with LDAP, and POSIX group semantics.