This can be done in a number of ways in Kite9:
Clicking the “multi” button
Normally in the editor, you can only select one element at a time. By clicking the multi button (shown below), you can select multiple elements at once.
You can also activate multiple selection by holding down the Shift, Ctrl or apple Cmd key: all of these achieve the same thing as clicking the multiple selection mode.
While in multiple-selection mode, you can also do a “Marquee” selection. That is, you can drag a rectangle over a group of elements to select all of the elements contained in the rectangle, as shown below.
Click on the background to unselect any selected elements. Some elements are containers of other elements. If you select the container, the elements it contains will automatically become unselected. Likewise, if you have a container selected, and you select some of it’s contents, it will become unselected.
So, you can’t select containers and their contents at the same time.