To make sure I understand, you want to move the x position of one field based on its heirarchical level but do not want to use the built in function in Group Heirachy becasue it moves all fields, correct?
YOu can right click on the field you want to move and select Size and Position
in the x portion use the formula field to chnegt he x position based on your criteria
use HierarchyLevel (GroupingLevel ({table.field})) in the formula to make positions move
an example to start 1/2 inch in and move 1/2 inch for each level would be
HierarchyLevel (GroupingLevel ({table.field})) * 720