You can find some examples in the Voicebox matlab toolbox:
http://www.ee.ic.ac.uk/hp/staff/dmb/voicebox/voicebox.html
At the Mathworks website you can find a possible answer:
https://www.mathworks.com/matlabcentral/fileexchange/32849-htk-mfcc-matlab/content/mfcc/mfcc.m
Can you post your own version or efforts?
Concerning your specific question about the filter banks:
Find maximum frequency in Mels: If your frequency range is 300Hz-8kHz for example you will have 401-2835 Mels (using freq. to Mels convertions).
Find bin center Mel freq: If you want 10 bins you must have 12 points eleven zones; so bin width=(2835-401)/11=222; the bins will be approx: bwm(i) = 401.3, 622.5, 843.8, 1065.0, 1286.3, 1507.5, 1728.8, 1950.0, 2171.2, 2392.5, 2613.8, 2835;
Convert Mel freq back to lin freq: values will be: bwf(i) = 300, 517, 782, 1104, 1496, 1973, 2554, 3262, 4123, 5171, 6446, 8000;
Then you can proceed with the calculations.
Some code:
f1=300;
f2=3700;
n=10;
fm1=2595*log10(1+f1/700);
fm2=2595*log10(1+f2/700);
fmw=(fm2-fm1)/(n+1);
fm=fm1:fmw:fm2;
f=700*(exp(fm/1125)-1);
% for plotting
x1=ones(1,n+2);
x1(1:2:(n+2))=0;
x2= zeros(1,n+2);
x2(1:2:(n+2))=1;
plot(f(1:11),x1(1:11))
hold on
plot(f(2:12),x2(2:12))
hold off