If you have a created a feed using Feed Builder, you can organize your content using Headers which will allow you to break the feed out into different topics or in-feed sections. The app example below shows two Header topics in its feed, "Stock" and "Travel & Outdoors":
To add headers to your feed, navigate to the selected custom feed build, and click +Item on the top right. Select Header.
Enter the copy of your Header and then select Save. Drag and drop the Header wherever you would like it to appear in the feed!