How to add content to workgroups
An individual item from your Sandbox
Go to "My Sandbox". Click on the metadata where you want to add the workgroup.
2. Click on Actions dropdown, then click on open item editor.
3. To add an individual item to a Workgroup, select the Workgroup you would like to move this item to.
4. Select
and the item will now be available in the selected Workgroup.
Multiple items to a single Workgroup from your Sandbox
Select the tick box next to the items you would like to add. Once you've selected the items, select the
dropdown and then 
2. Fill in what Workgroup you want to move the items to.
3. Select
and the items will now be available in the selected Workgroup.
Change Workgroup
How to change the Workgroup of an item that currently has a Workgroup
Go to the item page, click on the Actions dropdown and open item editor.
2. Under "Workgroup" select the Workgroup you would like to move this item to.
3. Once done, select
and the item will now be available in the new Workgroup.