I've been trying to get the XBMC devs to make "File" view be WYSIWYG (also show watched files even when "show only unwatched" is checked), which is along the same lines as what you're asking (toggle the filter depending of what part of the library you are in), and yes it is possible. The problem is that the conditional item used to set it to Unwatched or Watched can't put it back to what ever it was before (the skin would at that point force the filter on others that may not use them in the same way as you or me).
What we need is for different library areas to save their own watched/unwatched filter settings (Files remembers "All videos"; Recently Added remembers "Unwatched") and that is an XBMC issue. The library already treats "TV Shows" and "Movies" in this way (allowing each to have their own remembered filter), we just need the XBMC devs to expand that to all library elements (recent,files,playlists). IMHO at least.
Here are others with the same basic problem.
http://forum.xbmc.org/showthread.php?tid...+unwatched
However...
You can do sort of what you want without messing with the Watch/Unwatched filter issue by using a smart playlist.
Code:
<smartplaylist type="episodes">
<name>Recently Unwatched</name>
<match>all</match>
<rule field="dateadded" operator="inthelast">
<value>30</value>
</rule>
<rule field="playcount" operator="lessthan">
<value>1</value>
</rule>
<limit>100</limit>
<order direction="descending">dateadded</order>
</smartplaylist>
or through the GUI
will yield the same results, a list showing all the episodes added in the last 30 days that have not been fully viewed yet. (works with movies too)
Just added a custom submenu item to TV Shows, and point it to this playlist.
Funny thing is that you can't go the other route, because the watch/unwatched filter works in playlists too (which IMO should also be WYSIWYG), so if you have your filter set to Unwatched, and make a playlist that shows you only episodes "watched" in the last 30 days, it will be blank (unwatched is hiding the results). A further annoyance is that smart playlists process the "limit" before the "order", otherwise you wouldn't even have to add the "dateadded" condition. But I'm not a DEV and so I can't change any of that.