The tab consists of a topbar with following buttons and the map list:
The offline maps are listed under the topbar. Tap on the map name and in case your real position is within the map, the map launches into the main screen. Otherwise you are prompted that your position is outside the map and offered to have the map centered. If you positively know that your current position is not on the map and you want to display the map anyway, you can enter the map Action menu and select Center map option. It shifts the map to match its center and the center of your screen. If you want to center your screen on another place in the map, Locus Map provides Set new center that launches the Location Selector tool with several map center re-defining options. The map's Action menu contains also:
As is mentioned in the chapter about Online maps download, Locus Map stores downloaded maps into the Locus/Maps directory. It displays itself as the Maps folder in your Offline tab. The maps in it are sorted alphabetically as you named them.