AtkManyToOneTreeRelation

Relation: atkManyToOneTreeRelation API docs | Flags

Overview of other ATK relations Alphabetical list

atkManyToOneTreeRelation screenshot

The atkManyToOneTree relation will build a dropdown that looks like:

Record A
  Record B
  Record C
     Record D
     Record E
Record F

It could be used together with atkTreeNode with AF_PARENT.