The map gallery is started in ArcGIS Pro via the Share tab > Share As > Map Displays.
After opening the map gallery, a drop-down menu displays a list of available map displays.
If ArcGIS Pro is started from a VertiGIS project, only the map displays associated with the started VertiGIS project are displayed in the map gallery. Otherwise, all map displays that the actively signed-in user sees on the portal are loaded.
The map displays contained in the list can be selected by the property Topic to filter them.
Double-click to load one of the map displays in a new map area.