There are several ways to approach this. So I can move this to project so you can get comments on the various different methods.
The simplest way is to install the master so that it controls the load to the fixture.
Now install any dimming switch you want elsewhere, but do not use physical traveler wires to connect it to the master and do not use it to actually control the load to the fixture. Instead, just power it. Note that this device must be something that can talk to the smart things hub. So it cannot be the usual GE auxiliary switch, because those are not actually network devices at all. But it can be another GE master, or it can be a master of another brand.
Now Use any smart app you want to have the switches follow each other. You can just use them and dimmer or you can use something newer.
This creates a “virtual three-way.” The auxiliary is sending a request to the hub and the hub is sending the instruction to the master and the master is making actual adjustment.
Like I said, this is the easiest way. However, you will be missing a feature that you would have from an actual auxiliary which is that if your home automation system is not working, your master switch will still work, but your auxiliaries will not work at all. That may be OK for most use cases, but is just something you should be aware of.
Alternatively, you could go for zwave devices which do have dimming options in their auxiliaries.
Note that you should always match the auxiliary to the master that the manufacturer says it goes with. You cannot mix-and-match auxiliaries from other brands as the wiring differs.