Hi, wizard implementation can be found under
/libs/dam/gui/content/projects/addtask and drop-down can be found here
/libs/cq/gui/components/projects/admin/userpicker. Unfortunately both
those areas are marked as granite:InternalArea. Based on AEM
documentation Internal (granite:InternalArea) - Defines a node as
internal. Nodes classified as internal cannot be overlaid, inherited, or
used directly. These nodes are meant only for internal functionality of
AEM I have been assigned the same use case...