Does the temp-table definition mimic a DB table?
If so, then use the 'Procedure Settings' button to define Temp-Tables associated with DB tables. You can then select these when creating browses in the AppBuilder.
If not, then create your temp-table definition (in the Definitions section) then create a browse on your window. Then use the 'Freeform Query' button to associate the browse with your temp-table.
HTH,
Gordon