Openhab 3 Homekit KNX Thermostat setting

I am working on the migration of my 2.5.12 version to openhab 3. Most of it is working again, so far the good news.
Now I am trying to link my knx thermostats. I am able to display the current temperature and the target temperature with the following commands: Thermostat.CurrentTemperature and Thermostat.TargetTemperature.
In the OH 2 version I was able to set the temperature as well.

Now it is, in Homekit, only visible.

In the documentation I can not find the right command.
I am sure this should be possible.

it looks like the thermostat group is not configured correctly.
it display every item separately as single temperature sensor.
you need to put them in a group, e.g.

Group           gThermostat                "Thermostat"                                              {homekit="Thermostat"}
Number          thermostat_current_temp    "Thermostat Current Temp [%.1f C]"   (gThermostat)        {homekit="Thermostat.CurrentTemperature" [minValue=0, maxValue=40]}
Number          thermostat_target_temp     "Thermostat Target Temp[%.1f C]"     (gThermostat)        {homekit="Thermostat.TargetTemperature"  [minValue=10.5, maxValue=27]}
String          thermostat_current_mode    "Thermostat Current Mode"            (gThermostat)        {homekit="Thermostat.CurrentHeatingCoolingMode"}
String          thermostat_target_mode     "Thermostat Target Mode"             (gThermostat)        {homekit="Thermostat.TargetHeatingCoolingMode"}

That did the trick. The only thing I need to do it to change the .items file.
In OH2 I had everything grouped at actual temperature, another group with target temperature.

Actual Temperature:
Number KNXTemp1 "Entree [%.1f °C]" <temperature> (BG_BV,gTE,KNXTempBV) {channel="knx:device:bridge:generic:KNXTemp1"}

Target Temperature:
Number KNXTemp21 "Entree [%.1f °C]" <temperature> (BG_BV,gVWS,KNXTempBVS,gVWSP) {channel="knx:device:bridge:generic:KNXTemp21"}

Current mode:
Contact KNXVerw "Verwarmen / Koelen [MAP(]" <climate> (gTE) { channel="knx:device:bridge:generic:KNXVerw"}

I do no have an option for target mode right now. Can I just create it? Should I use a rule for that (if the target temp is higher than actual it needs to heat). Or are there other solutions.

In see that I need to familiarize myself with the logic of the thermostat. Do not catch completely the setting in the homekit (off, heating, cooling, auto).
For now auto is fine for me. It shows the actual temp in the left handcorner and the set temp under the name. Looks good to me.
Schermafbeelding 2021-02-01 om 19.52.33

it all depends on the capabilities of your physical device. does it support cooling or only heating? can it switch to OFF or HEATING mode based on current temperature?

if you device support different modes, e.g. OFF and HEAT, you can define TargetHeatingCoolingMode and control you device from home app.

if you device is able to switch heating or cooling mode based on a threshold, e.g. if temperature is below 15 switch to HEAT mode, you can define HeatingThresholdTemperature or CoolingThresholdTemperature to control these thresholds

with the next release of the homekit binding it will be possible to remove modes which you dont need, e.g. you could just keep HEAT and OFF, or just auto.

Thanks for the clarification.
As my thermostats are all linked to the same heat pump they are not able to switch it to heating mode or cooling mode.
The heat pump itself defines based on the outside temperature if it needs to cool. And if the temperature in one of the rooms is to low it will start heating.

Looking forward to the next release of the binding.