If you need a group for a use case, create one in Yammer.
Create a group
Select Create a group at the bottom of the Groups pane.
Select Internal Group or External Group.
Type in a Group Name.
Type in the names or emails of Group Members.
Select Public Access or Private Access.
Select Create Group.
Add information and customize the group's look
In your group, select Settings.
Type a brief statement in the Group Description about the purpose of your group.
To add a photo:
Go to the picture you want to use.
Select a color for the header.
Select a Group Pattern to give your group some design and personality.
If you need a group for a use case — like "New Hires," to start a community for onboarding new employees — create one in Yammer.
At the bottom of the Groups pane, select Create a group.
If it's not already selected, choose Internal Group.
Type in a Group Name, such as "New Hires".
And type in the names or emails of Group Members.
Decide if you want the group to be accessible to the entire network or just the members of the group.
Then select Create Group.
And your new community has been created.
Add information about your group, and customize the look of it to give members more context.
And type a brief statement in the Group Description about the purpose of your group.
To add a photo, select Add, go to the picture you want to use, and select Open.
Then select a color for the header.
And select a Group Pattern to give your group some design and personality.