You just need to include the fields of the Group table that you want to show.
Code:
SELECT Group.Supplier, Group.Series, Lines.SeriesConnectedToLines, Lines.FlatTrimOther, Lines.ShapeCode, Lines.Size, Lines.Descript, Lines.Price, Lines.Freight, [Price]+[Freight] AS Landed, [Landed]*1.75 AS [DLR A], Round([Landed]*1.5,2) AS [DLR B],
[List]*0.6 AS [WHL A],
[List]*0.65 AS [WHL B],
[List]*0.75 AS Retail, Int(100*[DLR A]+0.5)/50 AS List
FROM [Group] INNER JOIN Lines ON Group.SeriesID = Lines.[SeriesConnectedToLines]
WHERE (((Group.Series)="Amber Valley") AND ((Lines.FlatTrimOther)="Trim"));