short answer no split personality has nothing to do with dissociation.

longer answer. its a bit hard to explain but i will try...

split personality means a person thoughts and beliefs and behaviors are in focusing on either all good or all bad. they dont see things as being / having both pros and cons / positive and negatives. depending upon what they choose to focus on.

example a parent is both good and bad. they have to balance being a the fun mom and the set down boundaries/ rules, taking care of the child.

a child with split personality problems would see the mom as all good or all bad, no middle ground. dispite the parent playing a game with them and taking them to a playground the person may focus instead on all the things the person didnt like about their parent... such as thinking that veggie they had to eat when they didnt want to, the parent made them do their homework instead of watch tve, go to bed too early ...

focusing on all negatives or all positives never seeing both at the same time in everything. there are special therapies to help a person who has polorized (black and white or more commonly known separating people places things events into good and evil)

your treatment provider can explain more about how and why this is no longer called a dissociative disorder here in the USA.