Minyaa provides User Pickers able to simplify the User selection in your JIRA Issues. You are now able not only to filter but also to restrict the selection depending on Group or Role membership.
The User Picker by Groups allows to restrict the user selection to a scope of group.
The User Picker by Roles allows to restrict the user selection to a scope of role for the current project.
The User Picker by Permissions allows to restrict the user selection depending user's permissions in the current project.
Next steps : Mutli User Pickers by Groups and Roles ...