When capturing image sequences destined for focus stacking, you can use Capture One to select the appropriate sequence of images.
If the images are captured using the Focus Stacking tool on the XF Camera, you can select them by Sequence ID (metatag). Select one of the images from the sequence and then choose Select -> Select By Same -> Sequence ID. All the images with the same Sequence ID are now selected.
Otherwise, you will have to select the images manually. When the images are selected, they can be sent to Helicon Focus by going to the menu and choosing Image -> Edit With -> Stack in Helicon Focus.
A dialog will open. It will let you set up the output files that are used in Helicon Focus and some basic adjustments.
The Keep processed variants option can be checked if you want to store the processed work-files in order to have a faster workflow for re-processing the images through Helicon focus at a later time (please see below). When things are set up the way you need, click on the Edit Variants.
Now the selected images will be processed and imported to Helicon Focus. Afterwards, Helicon Focus will be opened.
In Helicon Focus, you should select your rendering method (please refer to the Helicon Focus Documentation) and click Render.
Once the Stacking image is rendered, you should click Save and the dialog will point you into the original capture folder. Save your image here and exit Helicon focus.
Back in Capture One, you should now see your complete image along with the saved variants, in case you selected to keep them.