User Level: 
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D8 - Groups - Add Group Menu - Navigate to Group Type

1. Go to Group Type

Go to Admin Menu > Groups > Group Types > Service > Manage Fields.

D8 - Groups - Add Group Menu - Click Content Tab

2. Go to Content Tab

Click the Content tab.

D8 - Groups - Add Group Menu - Install Group Menu

3. Install Group Menu

D8 - Groups - Add Group Menu - Install Content Plugin

4. Install Content Plugin

D8 - Groups - Add Group Menu - Click Configure Button

5. Configure Page Content

D8 - Groups - Add Group Menu - Check Add Group Menus

6. Add Group Menu to Page Content