CMS Made Simple CMSMS formbuilder custom dynamic pulldowns implement and instruct

Need to create a couple of customised pulldown menus within cmsms (CMS Made Simple) FormBuilder. The first pulldown needs to be dynamically populated with options/values from the cmsms database and needs to populate another pulldown below it dynamically depending on the selection from first pulldown. I need the solution to this to be all within cmsms admin using Formbuilder advanced section/javascript or whatever is recommended. Need the solution shown to be working and instructions fro me toi implement similar in the future.