Key Fields with no Value

One of our Developers has a query:

We have a map with multiple screens. The key fields are in the 1st screen’s table.
If we check In the 1st screen “filter duplicate rows”, then all data from the 2nd & 3rd screens is missing.

So, only way (I know) to specify key fields and set filters is in the corresponding java:

            //Adding primary keys to gx_table
                            GXITableColumn[] columns = {gx_tbl.getColumns().getColumn("Chain_Name"),
                                            gx_tbl.getColumns().getColumn("Chain_Id")};
                                            gx_tbl.setPrimaryKey(columns);

and

//Set filter on the rows which will remove all the empty rows from the table
gx_tbl.getRows().addFilter( new GXNonEmptyRowsFilter(gx_tbl.getPrimaryKey()));gx_tbl.getRows().filterRows();

//Set filter on the rows which will remove all the duplicate rows from the table
gx_tbl.getRows().addFilter( new GXNonDuplicateRowsFilter());gx_tbl.getRows().filterRows();

The problem is that on the total line, a key field, Chain_Id is blank & the line is not shown at all.
In order to show this line we have to change the Natural program to populate this field.

Is there a better solution to show a line where one of the key fields is blank?

Can you send some screenshots and a GCT file with the table?

Never mind. The Developer went another way.