Hi,
documents in user contribution web part are selected a similar way as here:
SELECT * FROM View_CMS_Tree_Joined_Versions WHERE ((((NodeSiteID = 2) AND (Published = 1)) AND (DocumentCulture = N'en-US')) AND (NodeAliasPath LIKE N'/Community/Wiki/%')) AND (ClassName IN ('CMS.SimpleArticle')) This view contains only document, node and SKU data. So you cannot filter these data using custom document type fields.
The way you can use is to use smart search module as was suggested in one of previous -email.
Or you can modify a contribution list control more and select data by your own in a custom
query data grid.
Best regards,
Ivana Tomanickova