A little puzzled with setting rx mux

Hi,
I think I’m a bit confused about the meaning of instructions like

self.u.set_mux(gru.hexint(0x01010101))
or
self.u.set_mux(gru.hexint(0xf3f2f1f0))

I mean what exactly do I tell to the set_mux method by each single
{0,1,2,3,or f}?

does for exmample a 3 in the 4th position mean that adc3 is connected to
the Q channel of DDC 1?

if so…
how can I obtain two demultiplated gr.complex flows coming from two
separate frontends (actually two DBSRX) one on rxA one and rxB side?

would

    self.u.set_mux(gru.hexint(0x01230123))
    self.connect(self.u,deinterleaver)
    self.connect((deinterleaver,0),fft_sink1)
    self.connect((deinterleaver,1),fft_sink2)

do what I need?

really thanks
vincenzo