You can send your content feeds from Feeds Box to a specific posting campaign.
Select a feed or a group of feeds and press WITH SELECTED button.
Press Add to a posting campaign.
Then choose a posting destination and a posting campaign from the list.
In the same way, you can send your content feeds to a posting campaign at the time you search or generate them.
And finally, you can add more feeds to a posting campaign from its editor. Go to the posting campaign editor and use Add content option in the Content section.
Note: there is a limit of content feeds per one posting campaign - 10 at a time. Also, be aware, as soon as you remove content feeds from the Feeds Box, they will be also removed from your posting campaigns.