If a group wiki is enabled, you will see the Wiki option in the sidebar on the group home page.

If the wiki option does not display, you can enable the group wiki from the Control Panel.
Procedure
1. Navigate to Control Panel Dashboard > System Administration > Group Administration > Groups. The list of groups displays in the workspace.
2. Click Edit to open a group.

The Group Options page displays.
3. Select Wiki Options.

4. Enable the Enable Wiki setting.

5. Click Save.