The Compare template allows you to create an app to present a side-by-side or stacked comparison of two maps or scenes. You can configure the app to compare two scenes, two maps, or one of each. The scenes or maps you compare can be linked, which means panning and zooming in one synchronizes the extent in the other, or leave them unlinked to allow users to explore each independently.
To see the options available for this template, search your ArcGIS Enterprise portal using the app template name and open the app template item's detail page.
You need two maps, two scenes, or one map and one scene.