Process Start White List defines who is permitted to start the process. By default, everyone can start the process. But when configured, only those found in the mapping will be allowed to do so.
Figure 1: Map Participants to Users - White List
Process Start White List has the same mapping options found in conventional participant mapping, thereby making available a wide range of options.
You may also write your own beanshell script or extend it using custom participant mapping plugin.
Figure 2: Map Participants to Users Mapping Options