Filtering by name or channel URL is something that will probably not be done very often.
I'll walk you through an example.
Let's say you have a lot of music-related channels and you would like to group them together. Open the Program Options, go to the Search page and create a new channel category called "Music" (by clicking on the appropriate icon in the top-right part of the category list). Click on OK to save your changes.
Go to the My Channels window and right-click on one of your music-related channels and open the Channel Categories sub-menu. You will see your new "Music" category there. Click on it so that it has a tick next it. This channel has now been assigned to the "Music" category. Do this for each channel you want to be in this category.
Open the Channel Filters dialog (in the View main menu) and create a new filter (by clicking on the yellow icon in the top-left corner). Call it "Music". In the Channel Categories part of the dialog, you will see a small button with an arrow pointing right. Click on it and add the "Music" category to the filter.
Press OK to save the new filter. This filter will now pick up any channels that have been assigned to the category "Music".
In the Organize Channel Filters dialog, if you now apply this filter, My Channels will refresh itself to show only those channels in the "Music" category. If you assign a hotkey to this filter e.g. CTRL-SHIFT-M, you will be able to show just these channels with a single keystroke.
Wow. Having typed all this in, it really is a bit complicated
One wizard coming up...