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 export the document in Photoshop or in the background when saving the image. separation channels before exporting.
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.