here is a good example of what mapping DID systems is in my location. its like making a family tree.... Dissociative Identity Disorder: Mapping Your System

being able to map ones system does not mean it invalidates the diagnosis. it just means the person with DID has enough co consciousness between their self and their alters to be aware of the alters, or they have been in therapy long enough for their treatment providers to be able to help them figure out which alters come from who and such (this link uses the term how the alters are related to each other and who is closer to who)

those that I know that have done this, they have done this over the course of years during therapy due to the way treatment providers in my location do not call out alters or expect any direct outcomes and do not put any expectations on the map making.

like I said before my own treatment providers and other treatment providers in my location preferred/ prefer doing the more natural approach of "charting"