The basic idea is: if the squares do not overlap then you need to tweek the offsets in Cura until they match perfectly. The dot indicates the direction to the origin (0,0) of the platform.Load both files, do a dual extrusion merge in Cura and print. The amf file seems not to work yet in Cura as it loads two seperated models, which you cannot merge. If you split the models they make a mess....