Use the Add contact dialog box to specify users or groups as participants in workflow processes, or to assign permissions for workflows. You can select either local or domain users and groups; you can also use fields to designate users or groups based on role-based field mappings.
If the workflow includes approvers or task recipients from different domains, a trust relationship must exist between the domains so that the users from both domains can log into the web application and complete their assigned tasks.
In the Contact type drop-down list, select User, Group, or Field. If you selected a user or a group, specify the contact location (local or domain). In the Search filter text box, type the contact name, or type the first few characters of the name and an asterisk, and then click Search. Select the contact(s) from the list and click OK. (You can use Ctrl or Shift to select multiple participants.)
For more information, see "Assigning process participants".