View Project Groups
When you have created several projects, you can group or ungroup them. On the project homepage, all your project groups are listed in the section called "Groups" on the left side.
To group projects together, go to the “Groups” section and click the settings icon there.
Then, click "Add" on the "Manage groups" window that pops out and give it a name.
You can also click the trash can icon to delete a project group. Note that if you delete a group, projects within the group will only become ungrouped, not deleted.