How to subtract polygons?
Select several polygons on your drawing.
Right click to enable the Context menu.
Click on the "Subtract" button there.
Choose the base polygon, which you want to subtract from.
Press the "Apply" button to save changes.
π Note!
If you've made a mistake with the selection of the base polygon, click on the checkmark near the base polygon selection status and make your choice again.
If you would like to save the initial polygons, press the "Keep polygons" setting.