I tried making a filter.
My comments: I quickly read your comments on making the filter. But didn't commit much to memory.
I could not get it to work. I first tried making a filter. I filled out the Title as "Dungeon" and the filter as "Dungeon" It gave me an error that the SQL query failed and then would not let me see any of my games until I restarted DBGL. I then tried Just filling out the title. It did not give me an error, but again would not let me see any games, in both tabs. I deleted the new tab and restarted DBGL. When writing this comment, I thought I would see what would happen (for your testing thoroughness) when I kept the Dungeon tab and then restarted it. When I started DSGL it said something like: "SQL Query in use by another process, can not start DSBL" (That is highly paraphrased) I tried opening it again and to my surprise it opened, further more both tabs were there and it was working!
Now, at any point in time I am only able to make one tab & can not make another even if I delete the tab until I restart DSGL after deleting it.
I found the Filter Adding Page Confusing. At first I though that the name was going to appear in the tab & had nothing to do with the filter. The "Info" at the top of the page Could Perhaps Read "Add a Filtered Tab"
The second "advanced" might be better to hide with a an Advanced Checkbox. When checked the SQL Query Box will come up. with a very consise description stating that one must construct a SQL Query with a link to some information like you posted in the blog.
I would comment more but the shortcut for adding a Tab is no longer working. I deleted "Dungeon" a couple of times and Deleted "Dungeon" with "Dungeon" in the second box 1 or 2 times. It failed to allow me to add a tab after deleting "tank" for the 1st or 2nd time.
Great idea. Hope my comments help.
Snow Leopard, Java 1.6.0_15