The Detail Floorplan is a set of templates that allow you to display data.
This article explains how to apply it to a Panel object.
If you have never applied the FioriMobile Pattern on your KB, read GeneXus for SAP Fiori Mobile Pattern. On the other hand, once you create a Panel for Smart Devices, the following window will be displayed showing a group of categories, each one offering templates.
If you select the Detail category, two templates are shown and you can select one to be applied to the Panel for Smart Devices:

-Data Display

-Display with Sections

Another way to apply it consists in opening an existing panel, right-clicking being in its Layout, and selecting Apply FioriMobile template to control:

To incorporate this into your App, read Genexus for SAP Fiori Mobile Pattern - Menu Floorplan