From reading into this a little more it appears to have been removed from the S10 range mid year via update - bit of a kick in the teeth for those that got to use it for a few months and not been able to on previous S models aside from S9+.
But, it's worth mentioning in the month before the S10's release this was reported:
"Samsung has also improved the Dual Capture feature in Live Focus mode. On current flagships with dual camera setups, the camera can save a picture from both the telephoto and regular lenses. On the S10, you will be also able to save a super wide-angle version of the same scene."
Whether that means they removed in the hopes of upgrading for the Note 10 range/maybe the option of Triple Capture/options in wider views i'm not sure. The change of having the wider view Live Focus makes me wonder - was this available on the S10 prior to Dual Captures removal, or was this Samsungs way of 'replacing' it? (Saying 'replacing' because lets face it, it's a downgrade.)
Samsung even still advertise this as available on the S10 range and the Fold range on this webpage:
"Dual Caprture is available on Galaxy S10e, S10, S10+, Fold, Note9, and S9+." (Note the typo)
So, so frustrating.
Great research, thanks Piggy. This makes me hope that Dual capture is maybe coming back or the Triple capture as the article suggests but I wasnt aware that they reomoved it from the S10s! thank you for that piece of information because I was actually on a verge of swapping my Note 10+ for a S10+ and it would have been for nothing !
Just to add to that research, i've just found a video showing the features of the S10 camera right around release date - it wasn't present there either so looks like it never was. So, what this says to me is that the filters that we can now apply in Live Focus are what we've been given as a replacement last minute. If they were promising Dual Capture or even Triple Capture in the new range, they obviously couldn't get it working.
If they would at least say it's being developed that would be a start..