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With nothing selected, in the Edit menu, click on Add Group. You can give the new group a name and customize the icon.
Once it is created, you will see a new group in the left column.
Before exiting the program, don't forget to save the changes to the database.
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Left click on a group. Then in the Edit menu, select Add Subgroup.
Once created, the subgroup will be visible in the left column.
Before exiting the program, don't forget to save the changes to the database.
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