It has been a while since I last did much with filtergraph~, but I believe that you can first use a filtergraph~ object in lowpass mode to determine a set of (five) coefficients that you want for each biquad. This would show you the response for 12 dB/octave.
For 24 dB/octave rolloff you then replicate this list and use the exact same coefficients for each of two cascaded biquads in a cascade~ object. In order to see the response curve of this 24 dB/octave cascaded filter you can send the replicated list, now with ten coefficients, into a second filtergraph~ object as part of a ‘cascade’ message (where this second filtergraph~ has already been set to mode 0, display mode).
For 48 dB/octave you would do the same but replicate the coefficients four times to have 20 coefficients, four identical sets of five. And so on.
I won’t guarantee that this is the best way to do these things. As with any kind of real programming—and Max is real programming, after all—there are almost always many ways to do more or less the same thing. In time you develop your own style and favourite way to do things, just as with creating music; no one person’s music is ‘correct’. Also, filter design is a rather deep rabbit hole once you begin to play with it. Nonetheless, the above is what I would start with, and I believe it should work.
For a bit of detail about the messages you need, in particular the ‘mode’ (or ‘display’, equivalent to ‘mode 0’) and ‘cascade’ messages, see:
https://docs.cycling74.com/max8/refpages/filtergraph~MacBook Pro, macOS Sonoma 14.4.1, 2.3GHz i7-1068NG7, 32GB – Live Suite 12.0.1, Max 8.6.2, Push 2, Scarlett 4i4
