You may change the Creditor group 1 and / or 2  for selected creditor (supplier / vendor) account(s). 

To change the Creditor group 1 or 2: 

1.On the Creditors (Creditors list) (Action ribbon), select the creditor (supplier / vendor) account(s).

If you need to select multiple creditor (supplier / vendor) account(s), press the Ctrl or Shift key and click on each creditor (supplier / vendor) account, for which you need to change the creditor reporting group.

2.Right-click and select "Creditor group 1" or "Creditor group 2" on the context menu. 

3.Select "Empty" or the available creditor group from the sub-menu. The "Creditor group 1" or "Creditor group 2" will change on reports. 

creditors-context-menu-change-reporting-group