How to Create a Custom Group and Assign to items
To create a Custom Group, go to Products Catalog->Custom group tab.
Then, expand the appropriate group listing and click on the + sign to add a new group.
Name the group and click the checkmark to confirm. Be sure to click SAVE when finished.
The final step is to assign the custom group to items.
Click the Products catalog tab and select the desired items. Then, click BATCH EDIT ATTRIBUTES from the action button:
Click in the Custom Group field to assign the appropriate custom group name. Then confirm items selected and click ok to assign.