Create a level Data as other level Data. Setup the fields. You can copy the Level_DungeonOutpost.
In the module parts, you need to add or edit the LevelAreaModule :
areaSpawnDepth : 100 (option not used and not reliable set higher than the max number of area in the dungeon to avoid issues)
areaDespawnDepth : 100 (option not used and not reliable set higher than the max number of areas in the dungeon to avoid issues)
areaCullDepth : 2, the depth at which point the area will be culled out.
ListAreabyLenghtAndDifficulty : This is where you can choose the dungeon to spawn by Lenght and by Difficulty. It is a list of list first index length chosen, second index difficulty chosen. Data :
areaCollectionId : The Id of the dungeon or the fixlayout to spawn.
numberOfCreature : the number max creature to spawn it will try to split them equally in the different areas.
IsSharedNPCAlert : if the npc are allowed to share alert in the area.