You cannot filter them. But you can select them by clicking the respective panel on the status bar.
https://winscp.net/eng/docs/ui_synchronize_checklist#selecting_actions

Yeah I did in the end.
One slight issue I found with that was the just was just huge.
Would be nice if we had buttons to let us filter:
Not on local but on remote
Not on remote but on local
Different between the two locations
And same

Then we could easily filter what we want to copy which way.

Ok, I'll see if more people ask for this.
Meanwhile, you can use Synchronization. It will show you the unmatching subfolders in the preview window.
https://winscp.net/eng/docs/ui_synchronize_checklist

Agreed sorry. My mistake.

Is there any possibility of having an option to get it to also compare directories (not sub directories).
This is a frequent task when trying to see what folders in a big list I need to upload that are missing.

Yes, as the documentation, I've linked above, says.

Thanks for the fast reply.
Great app and thanks for all the work.

It's not sub directories I'm trying to check. I'm not worried about whether the content of the sub directories are the same, just whether the actual folders in front of me are the same, not their content.

I think I worked out the issue anyway, this function/feature only compares files and doesn't include the folders into the comparison.

Indeed, the subfolders are not considered by the "Compare directories" function:
https://winscp.net/eng/docs/task_compare_directories

Hi,
I am using v5.19.5 and when I do 'Compare directories' between my remote FTP site (right panel) and my local folder (left panel) it is telling me 'No Differences Found' despite the fact I can see that the left panel has a significant number of folders that are not in the right and visa versa.
I was hoping it would highlight to me which folders are different between each side.