clear row.Item; itm_list = List(); rem_list = List(); fet_cat = Expense_Item[Expense_Categories == input.Category].ID.getAll(); itm_list.addAll(fet_cat); for each val in input.Item { if(val.Item != null) { rem_list.add(val.Item); } } if(itm_list.size() > 0 && rem_list.size() > 0) { itm_list.removeAll(rem_list); row.Item:ui.add(itm_list); } else { row.Item:ui.add(itm_list); }