Haha "please patch the game to add a feature that is already in the game!"
Sound about right.
You obviously skipped the tutorial dungeon since you can't finish it without separating your characters.
Drag any character portrait to the right to break them from the grouping.
I guess I'm not being clear. I'm fully aware that you can break the chains which bond your party together. However, once separated you can only select your characters by clicking on their portrait. I'd prefer if you could select your characters by simply left clicking on their model in the playable space - which makes it faster to issue movement commands.
So for instance, let's say I want to move two characters to opposite sides of a room. After breaking the chain bonds to separate those characters out of the party, I then have to select the portrait of the first character I want to move, then left click on the map to move them to the correct location. I then need to select the next character's portrait that I want to move and repeat the process. I'm covering a hell of a lot more screen space with my mouse than is necessary. Just allow me to separate my party, click on a character model (not portrait), then click where I want them to go.
It's not game-breaking by any means, it's just cumbersome compared to Balder's Gate, Fallout, IceWind Dale, etc. as practically all prior CRPG's followed the control scheme I'm describing.