If you have an event that needs to be moved into a grouping -- whether an existing grouping or a new one -- you can do that easily from the event details page.
- Related reading: All About Groupings
On the event's details page, click Actions then hover over Grouping and choose whether you'd like to add your event to an existing grouping or create a new grouping.
If you choose "Move to Existing Grouping", search for the grouping, choose the one you wish, and click save. Your event will now be in that grouping.
If you choose "Move to New Grouping", type the name of the new grouping and click save. The new grouping will be created and your event will be in it.