Add separators by clicking Add Separator on your Comping Tool tab bar. Separators are added on the cursor's location. Move the cursor by dragging the cursor inside the Comping Tool or repositioning it on the main MixPad window. Note that if cursor is not in the Comping Tool, left click moves the cursor inside the Comping region. You can also drag separators to reposition them. Right click on a separator deletes it. Select the desired part via left click on its region.