Hi and welcome to Arturia forums.
You can use the GATE BUS switches, - the FM setting (by standard i believe it's hardwired to bus 1), - and for example the SKIP or RESET function setting for bus 3, - and the TEMPO setting to get some rythmic results.
(Also you have the MIDI sync switch (missing a label at the moment.))
In your example i think you for example could do something like this:
1. Set the ARP sequencer to run 3 times tempo, the FM to no modulation, and use 3, 6 or 12 sequencer steps by using SKIP/ RESET function on Bus 3 for the steps that's not used/ or to return to step 1. In this case if you for example use 12 steps then when it run twice it's 24 steps but as 2 x 12 steps.
or
2. Set it to run in Tempo and then use 3, 6 or 12 sequencer steps with the FM set to 3 times Tempo and only use Bus
or
3. Set it to run in Tempo and use different busses and use the FM set to 6. Then each step on bus 1 play a 1/24 note, the notes on bus 2 play 1/4 note, and if you use the SKIP function the steps on bus 3 is skipped.
I have done this in my head only. I can only say that i would try things like this out to see how it works. I'm not an expert. I can only suggest you experiment and are creative.
Perhaps someone have tried to do the things you wan't to do and can chip in.