Displaying and using a list of UNIQUE values from a find

When searching through a table (called KPI - see below), there will be multiple entries for each date per client (one for each department).  There is a extra field, called committed, that gets flagged when a record is marked as "complete".  Basically, I want to display of list dates for the selected client where there are records that are not committed.  From there, the user will select a date, which will set the g_Selected Date global field in a table higher up in the relationship, and take them to the layout for that date.  The global field and the layout is already in use and working fine.  I just don't know how to show a list of "unique dates" from the KPI table for the selected client where the committed field is 0.  I'm also looking for suggestions on the easiest way to do this - a value list, a portal, something else?  Of note - this database is plublished via IWP, so the solution has to work there.
 
 
 
Table Structure:
 
Client (parent)
 - client ID
 - g_Selected Date (global field to pass date to another layout)
 
Department (child; many depts linked to one client)
 - dept ID
 - client ID (linked to client table)
 
KPI (grandchild; many KPIs to one client, one per date for each department ID)
 - dept ID
 - KPI date
 - KPI 1
 - KPI 2
 - Committed (0 or 1)