Definitely not as you've shown it, you cannot take a 12V and 24V supply from all of the cells, as your additional wiring is effectively short circuiting both groups of 4 cells.
Taking a 12V supply from just half the pack would be possible, although not recommended, as it would discharge the pack very unevenly. This would also put a high load on your
BMS and greatly increase your charging time as the
BMS struggled to balance the unevenly discharged cells.
The best way to provide a 12V output from a 24V battery would be to use a
24V to 12V DC/DC converter to drop the voltage down to 12V, but you will need to ensure that the maximum current rating of the DC/DC converter is sufficient for all of your 12V requirements.
Alan
