Control nfilters on Filtergraph~

i feel like i'm not quite understanding your question: did you get this patch from someone else? it seems you already have control going to the inlets of the filtergraph~, and controlling the coefficients directly by number is not the most intuitive, anyways, might be much easier to just use the UI itself by locking the patch, and then dragging with your mouse over the center of each filter graphed within filtergraph~ to control cutoff and amplitude, move right/left for cutoff, and up/down for gain:

and drag over the enclosing 'sides' of each filter graphed in filtergraph~(showing the bandwidth boundaries) to control resonance:

hope i understood, if not, feel free to explain further what you need and i or someone else can try and explain from that context. hope this helps.