To transfer a clipboard from your personal locker to your groups locker, use the top left navigation bar to visit your profile. Once on your profile, visit the Lockers tab
Find the desired clipboard in your locker and press the Share button on the top left of the clipboard.
Clicking the Share button will prompt you to select which group you want to share the clipboard to. You will find all groups that you are a member of on this list. Click the toggle button on the group you would like to share to.
Your clipboard will now appear in your groups Pins section, where the group admin can review and add the clipboard to the groups locker.