It would help to see what kind of code you've already tried in order to accomplish this task with your Listdatasource. I tend to keep my master and detail grids separate, repopulating the child when the focused row is changed, so I wonder if this kind of pattern would help. It presumes master and detail would be linked by a parentID key in both tables.
private void Parentgv_FocusedRowChanged(object sender, DevExpress.XtraGrid.Views.Base.FocusedRowChangedEventArgs e)
{
int parentID = Parentgv.GetRowCellValue(Parentgv.FocusedRowHandle, colparentID);
childgc.datasource = childtable(c=>c.parentID == parentID);
}