It's just a very basic player that has "tree walking" ability for groups. Nothing more, nothing less.
It gives up all the channel sharing ability and other good things we use Emby for. No EPG or anything.
If Emby added GROUPS it would have the same functionality plug a lot more.
If you are at all handy with small programming jobs or scripting and can open, read & write files you could do something similar for Emby but without the need for any plugin. Just read in the XLM file and then write out STRM files for each channel. You then put these in a "Live TV Library" setup as Home Videos. You could have LEVEL 1 folder as the group and then all channels in that group as strm files in that folder. Each channel could then be part of one or more groups (just write it out multiple times).
That would give you a very similar navigation structure that is usuable as a library. It would also not be limited to a single source either. You could read in a dozen or more XML files and write out the STRM files for each channel into a group folder. You could even download the linked graphic (if there) and write it as the folder image as well.
STRM files allow all kinds of cool things like this to be done.