Are you happy if your adenium plant can have different flowers blooming within one plant?
The answer to have different type of flower blooming is 'grafting' . The Multilayer adenium flower is from the grafted part (the upper part), while the single layer adenium flower is from the original adenium plant (the lower part). Most of the people will not keep the branch that grow from the original adenium plant.
I grafted this adenium early of the year or last year. The multilayer adenium flower is called sweetheart. Both multilayer & normal type blooming are sweet to me