Group each sub-element and the nodes that make up its left-right tree.
Select the group, choose Grouping, and View Group Content. You can also Press Alt+Page Down or simply double-click on the group background. This hoists the group so that only the contents of the group are in the workspace.
Apply your preferred left-right layout.
Choose Grouping, Previous View (or Alt+Page Up) to return to the full view.
Repeat this for each of your groups. When complete, close each of the groups and apply your preferred top-down layout. You may need to resize the closed groups before applying the top-down layout to leave enough room. The layout will not apply to the contents of the closed groups.
Open one or more of the closed groups to see the left-right content.