You can create folders to group your albums. For example, you could create a folder named “Family Photos” and put all the albums of your family events into it. You can also create folders inside other folders. You can only create folders in the Albums pane of Photos, not in any other pane.
Click Albums in the toolbar.
Choose File > New Folder.
Type a name for the folder.
Drag albums into the folder.
To remove an item from a folder, Control-click the item, then choose Move Album Out Of [folder name]. You can’t move shared albums into a folder.