These classes can be used to represent group relations. Since they allow DNs as members you can also use them to represent nested groups.
Activate the account type "Group of names" in your LAM server profile to use these account modules. Alternatively, you can use the account type "Groups".
Then add the module "Group of names (groupOfNames)", "Group of unique names (groupOfUniqueNames)" or "Group of members (groupOfMembers)".
On the module settings tab you set some options like the display format for members/owners and if fields like description should not be displayed.
Group of (unique) names have four basic attributes:
Name: a unique name for the group
Description: optional description
Owner: the account which owns this group (optional)
Members: the members of the group (at least one is required)
You can add any accounts as members. This includes other groups which leads to nested groups.
To show members of nested groups click on "Show effective members". Please note that for large groups this will run lots of queries against your LDAP server.