Is your feature request related to a problem? Please describe.
Recently, I decided to break my long-standing habit of only having one faction per realm, and (re)discovered why I'd been structuring my characters the way I had been. Currently, Bagnon (BagBrother?) tracks your inventories and gold on a per-realm basis, but has no regard for which faction a character is on. This makes it difficult to tell what items are actually available to each character at a glance, and incredibly difficult/impossible to tell how much gold is available on a faction without manually doing the math.

At one point I briefly flirted with the idea of using Bagnon on one faction and Combuctor on the other, but realized pretty quick that as they both use BagBrother to gather and store the data, that wouldn't actually solve the issue I'm having. (Unrelated: I'm not sure what causes the character sort order, though it does seem to be consistent across the addon; it's not alphabetical, it's not date of data creation, it's not based on my character selection screen's order (I don't even think you can pull that data), it's not by faction or by class, and it's not the same on my other 10-character server as it is on this one. Now I'm curious about that too, heh)

Describe the solution you'd like
Some sort of toggle (either in Interface Options or via a slash command since I don't think BagBrother has its own interface) would allow players to hide or show the data for the faction their active character is not currently on. There are situations where having access to the opposite faction's data IS valuable (a player with two accounts can use the auction house to "trade" things to themselves across the faction line, and Bind on Account items can be mailed freely across it) so whether the default is to show both factions (as now) or to hide the opposite faction is largely up to you. I think having the BoA items either show regardless or have a separate (nested) toggle for them would be pretty fantastic as well, but I feel like that would be significantly more work on top for what would end up being a very limited payout.

Describe alternatives you've considered
If there were a way to run two different versions of BagBrother and only have it turned on/collecting data on the correct characters, in much the way I originally attempted to have Bagnon on my Horde characters and Combuctor installed for my Alliance ones, that might work as well, but that seems like a lot of work (both to clone BagBrother and keep the clone up-to-date, as well as on the client end of making sure it's only enabled on the correct characters). I briefly thought having a visibility toggle on the character list (an eyeball icon next to the X-to-delete icon, perhaps?) might work as well, though that might need to be on a per-character basis which could get confusing if someone is using account-wide settings for everything else.

Sorting the characters by faction (so that in the lists that pop up, all the Alliance were always at the top and all the Horde were at the bottom, or vice verse) or changing the display colour of characters of the opposite faction ("greying them out" while continuing to display their data) would also at least go a little way in making it easier to tell at a glance that Alliance-side I had less than 50k gold, and Horde-side I was just over 175k, but that still feels not nearly as convenient as being able to mouse over my character gold on my single-faction servers and knowing how much gold I have to spend on that faction at a glance.

I second this; this had been resolved back in the day: #245

Definitely weird... Why would we want to see info about the opposite faction if the 2 factions can't trade with each other? I really hope they at least add an option in the settings for if we want to view our chars from the other faction or not...