Connecting the oven and hob to a five-wire cable

If the electrical appliance is single-phase, then it is connected to one phase: for one device, take any phase, for the second, take any of the two remaining ones. The third phase will not be used. Zero will be common for two electrical appliances, the ground will also. To connect, you need a terminal block that will have enough terminals to branch off the neutral and ground conductors. Also, this terminal block must withstand the load of these electrical appliances.
But before connecting, you need to make sure that your cable can withstand the load of these two electrical appliances. In this case, pay attention to zero - it must withstand the total load of these electrical appliances.
If the cross-section does not allow connecting such a load, then, as an option, one of the phases, to which nothing will be connected, should be disconnected from the machine in the dashboard and this wire should be connected to zero. And then you will have five cores: two zeros, two phases and a grounding conductor. But also this option can only be practiced if your cable can withstand this load.