Hiding Nodes with Just One Child
Hiding nodes with just one child is a filter operation that is similar to conditional row suppression. Nodes in a display hierarchy that only have one child are hidden. This function is a setting for the hierarchy in the characteristic. If several characteristics are on the same axis, they are processed one after the other, always starting from the outermost characteristic and working inwards (in other words, left to right or top to bottom).
Query Designer
In the Characteristic Properties screen on the Hierarchy tab, you can specify for a specific characteristic whether you want to always show or hide nodes with only with child, by using the hierarchy parameter Nodes with Only One Child.
Query Designer Documentation