❖Select by layer allows you to select elements in a target layer by selecting elements in another layer such as a polygon layer; all elements of the target layer contained within the polygon you select will also be selected:
In the dialogue that comes up choose the target layer by Layer to select from and the polygon layer by Layer to select with.
❖Now, in your scene select a polygon using one of the selection tools and all elements form your target layer contained in that polygon will be selected as well:
As you unselect polygons, so will the contained elements be unselected:
