You can use a selection window to edit a group of nodes, even if the nodes belong to different objects.

Activate the Edit Tool. To select multiple objects use the Shift key. You can use Ctrl+A to select all objects for node editing.
Use a selection window to enclose all the nodes you want to edit.
The selected nodes turn from blue to magenta. When you move any of the selected nodes, all nodes move as a group.
To deselect nodes, draw an "empty" selection window (one that does not encompass any nodes).

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