Roles in Maximo are used to represent a specific person or a group of people that can be used in workflows, communication templates and escalations.
If you need to find which roles are used in a specific workflow you can use an SQL query like this.
SELECT wfnode.title, wfnode.description, wfa.roleid, r.description
JOIN wfassignment wfa ON wfa.nodeid=wfnode.nodeid AND wfa.processrev=wfnode.processrev AND wfa.assigncode IS NULL
JOIN maxrole r ON r.maxrole=wfa.roleid
WHERE wfnode.processname='[PNAME]' AND wfnode.processrev=[PREV] AND wfnode.nodetype='WFTASK'
ORDER BY wfnode.title;
Just replace the [PNAME] and [PVER] tags with the correct process name and revision.