In case you are working with MeanWell LED drivers (like their HLG/XLG/ELG family) or any other driver that provides a constant current at the DIM input, you just need to select a potentiometer with suitable resistance.

Assuming the driver sources a constant current of 100uA (like MeanWell drivers do), 100kOhm are required to produce a dimming voltage of 10V: $$R=\frac{U}{I}=\frac{10V}{100\mu A}=100 k\Omega$$
If there is more than one driver, the currents of the individual drivers add up and a smaller resistance is required to get 10V respectively: $$R=\frac{10V}{200\mu A}=50 k\Omega$$

In general, to control `n` drivers with one potentiometer you need to choose one with a resistance of
$$R=\frac{U}{I}=\frac{10V}{n \cdot 100\mu A}=\frac{100}{n} k\Omega$$

The drivers' DIM inputs will be connected in parallel (all DIM+ go to one pot terminal, all DIM- to the other).
I've not found any information about how many meanwell drivers can be controlled with one potentiometer, but in principle there should be no limit. In practice, the potentiometer will have a maximum allowed power/current consumption you should not exceed.