For UIKit and Theme Cosmos based application the authoring of a repeating dynamic layouts (RDL) is an experience to be completed in Dev Studio. Templated sections cannot represent the configuration of a RDL, but they can reference non-templated sections that define this configuration. UI authoring in App Studio will allow a user to add relevant sections, even those authored in Dev Studio, to a templated section.
The UI Authoring experience for Cosmos React applications allows for defining RDL display for Page list properties. To add a RDL to a view in a Cosmos React application, the page list field needs to be added to a form. Using the configuration options, the field needs to be configured to be in read-only mode and to display as a field group. When this configuration is made you can choose the view to display an index in the page list.