XnView Software

In the folder tree it would be very helpful if you could select more than one folder (ctrl-click) and the files shown are from the selected folders. Subfolders view would show the subfolder items from all of them.

David

I doubt there is an app that works it this way as there will be too much confusion.

use Albums (virtual collections)
although there is no recursive view yet:
Browser - Album - add flattened view

Well it's just that I can easily need it myself innumerable times a day in different combinations, so I wouldn't want to be assigning anything, just clicking on multiple folders as needed. I'm sure others will need to do similarly at different times.
I wouldn't envisage that there should be a fundamental coding issue, since the thumb pane is just a list of files (you can for example display file lists with files from all over the place), more just a case of being able to select several folders in some simple way, with the file area showing the list accordingly.

You can get the same result with a Search or Smart Albums.

In the Search dialog, leave the main Filename and Folder fields empty, and add multiple conditions using Pathname or Folder, global match Any.

For example, if you do this with "Pathname Contains V:/Photos" then you will get all files in the recursive subdirectories of V:\Photos.

Or, you could do two conditions (again, global match Any): "Folder name IS Folder-A" , "Folder name IS Folder-B" and you will get all files in those two folders, non-recursive.

You can also shift-click or ctrl-click on Smart Albums to see multiple Smart Albums at the same time, which you cannot do with folders.

(FYI, I noticed that even on windows, Pathname requires / as the directory separator and not \. I've made Pierre aware so this should get corrected.)

I understand it's not as easy as clicking, but you can get the resulting set of files that is required this way.

If you are needing to do this "innumerable" times per day, then it sounds like you have organized your folder structure in a way that does not correspond to how you commonly need to retrieve them. Saved Searches or Smart Albums can serve as an alternative to reorganizing your folder structure.

Creating criteria as you suggest doesn't work well with needing the task a lot.
The reason I myself need it a lot isn't an artifact of bad foldering, but rather because I have a lot of plant photos and I often study some aspect. For example if I want to look at the hairier forms of plant, or items early in the year, doubtful ones, ones growing in drier spots, or something else, it's helpful to click on the folders containing those examples so they can all be seen together without other aspects intruding. It isn't something that needs to be saved, but just multi-selecting of folders will do it.
Or I might select them all and then gradually reduce the selection by unclicking folders.
I have them in about 30000 folders (which is partly laziness as if they were fully organised there would be many times more).
That may seem specific but if I were for example an artist or photographer of other things I might want to do similar things for artwork, for example clicking dogs and cats.
d

meteorquake wrote: Wed Dec 10, 2025 9:02 pm That may seem specific but if I were for example an artist or photographer of other things I might want to do similar things for artwork, for example clicking dogs and cats.

No, an artist or photographer would be using tags or keywords, not trying to filter down through 30000 folders. For that number of images, relying on folders rather than using the capabilities of the database is extremely inefficient.

Folders is definitely the right approach for the task, and a database the incorrect one. They are stored in a genetic (taxonomical) tree and within the final folder nodes by locational area or where needed by individual plant.
We're talking about categorisation that's utilised on the fly and transitory so you choose the folders per task, so formally categorising them doesn't make any sense... multi-selecting folders for the task however does

Haha, ok you’ve convinced yourself, so good luck with it.

I don't have any choice... the other workaround is copying the folders of interest to a RAM drive but it's not as good as selecting folders. I also use voidtools Everything that allows multiselection but the thumbnailing is not as effective as xnview.
I think it basically needs to be realised that some tasks don't work using formal categorisation.
For example, if someone asks for the identification of a plant that's unusual, I'll click on the folders that nearest match it and scrutinise the images. I'll then post up a comment on it and the 'categorisation' is never used again, because it is transitory. Creating millions of categories you'll never use again and constantly adjusting them as you use them is cumbersome and doesn't make sense.