After you modifications on channels and filters you can and export your image in different file options based on the RGB image from 'Export RGB' tab list.
You have the option to disable separation channels before exporting. It keeps your separation embedded in your image file, but it won't create the channel in generate file. The option appears when clicking on 'Make' and allows you to choose the visible enabled channels or all channels for exportations.
Exports alpha channels separations without RGB channels. The superposition coloring method 'Pigment' will be applied in the separated channel.
Exports alpha channels separations including RGB channels but excluding the separations area on the RGB channels. The superposition coloring method 'Multiply' will be applied in the separated channel.