Hi,

There's no easy way to leave a gap like that. You could set the ColumnSpan on column A in the parent band to 2 to have it span across both A and B in the child band.

Another option would be to create an extra column in the root band and then use a CreationFilter or a DrawFilter to prevent that column from appearing on the screen. But it would be tricky to get all of the borders right, since cells rely on their adjacent cells to draw borders.