grouping a table when linked to another ignores linking and builds groups on full dataset

## Bug Report

### Steps to Reproduce:
link childOrders to parentOrders
select a row from parentOrders, typically whittles childOrders down to a few hundred rows
group childOrders by exchange

### Expected Result:
the grouped rows still represent the rows associated with the selecte dparent

### Actual Result:
the groups are built from the entire table