I would like to use the category selector to group several values into a smaller number of values and it seems like +Override option would do this, but I can't find any clear instructions on how to apply this. I have added 2 categories, but nothing happens. I was hoping I could define several different values that I could group into each of the new categories I added, but I don't seem to have the option to do this. I don't know what other point there would be to having this option, though.
If anyone could provide even a link that explains, I'd appreciate it. I have Googled and searched and not found anything.