Specify which temperature ... above. Not quite. In virtually ALL mobos, the ONLY choice for which temperature sensor is used to guide the CPU_FAN header is the one inside the CPU chip. This prevents users from making the WRONG choce by mistake. Many mobos DO give you that choice on their SYS_FAN or CHA_FAN headers, though. Thus it MAY be possible to have one of those headers re-purposed to govern their cooling actions by the internal CPU temp sensor.
But there's another solution. The simpler one above is a fan Spltter to connect several fans to the one CPU_FAN header. A Splitter has only one input "arm" that plugs into that header, and two or more male (with pins) outputs for fans. It gets no power from anywhere else, so this sytem IS limited to the max current available from the CPU_FAN header. But note that this is really the only way to control the speeds of THREE-pin fans that use the older Voltage Control Mode (aka DC Mode). IF the fans you are going to use are the newer FOUR-pin fans (aka PWM Mode fans), then there is a different device you can use provided that the mobo CPU_FAN header does (or can be set to) use PWM Mode, and almost ALL current mobos make that possible. A HUB has the same input (female) connector and several outputs for fans, but it also has a third "arm" that must connect to a power output (either SATA or 4-pin Molex) from the PSU. All power for the fans comes from there, so you are not limited by the current capacity of the CPU_FAN header. That is the simpler way to connect many fans to one header. As I said, though, a HUB normally works only with a header configured to use PWM Mode, and with 4-pin fans.