Before linking a heading to an item, you must add the headings you require.
Open the Lists screen.
Click the arrow and select the required list.
Check Use grouping and filtering by user group for this list (upper right).
Go to the Headings tab.
Click the Add button below the Headings list to add a new heading.
In the dialog, enter the required name for the heading and a description (if required).
This is a mandatory field and must therefore be filled in.
Click Save to save the changes or Cancel to reject them.
The item is added to the Headings list. Repeat this procedure to add more headings.
After adding the required headings, choose which headings each item will be displayed under.