No setting needed. You only have to care about the storing method which I described in the other post. Look at the datfile and which setnames it uses and think again how you store them on your disk and how your rom path needs to be selected...
So for example for the titles datfile which includes also software list titles, you will see setnames like 3do_m2, 32x, a800 .....titles .....xegs.
Your rompath needs to be setup as a folder which contains the mentioned ones...for example:
"F:\MAME\Progetto\progetto-SNAPS - Titles" and then you e.g. have "F:\MAME\Progetto\progetto-SNAPS - Titles\titles" with F:\MAME\Progetto\progetto-SNAPS - Titles\titles\1on1gov.png .... F:\MAME\Progetto\progetto-SNAPS - Titles\titles\zzzap_audio.png in it...
So, "titles" is a setname, "F:\MAME\Progetto\progetto-SNAPS - Titles" is a rompath.
The non software list progetto dat (progetto-SNAPS - Titles NS) only has 1 set: "titles". So your setup rompath needs to be a folder which contains that setfolder and it should not be that folder.
again:
rompath\setname\file 1... file n
rompath\setname.zip (.rar/.7z)
the set, no matter if archive or folder is just a container holding single files for the specific set.....in the progetto snaps world you often only have 1 set containing thousands of files (the pngs)
Also keep in mind that anything which is in a rompath and doesn't belong to the loaded dat becomes unneeded.
So don't think about storing all progetto snaps collections in one rompath....you will need some kind of double folder structure:
F:\MAME\Progetto\progetto-SNAPS - Artwork Preview
F:\MAME\Progetto\progetto-SNAPS - Cabinets
F:\MAME\Progetto\progetto-SNAPS - Control Panels
and so on where the upper ones hold the setfolders...
F:\MAME\Progetto\progetto-SNAPS - Artwork Preview\artpreview
F:\MAME\Progetto\progetto-SNAPS - Cabinets\cabinets
F:\MAME\Progetto\progetto-SNAPS - Control Panels\cpanel
and so on...