As nobody else has bitten I will try.
If you mean navigation getting from A to B then pitch doesn't really come into it.
But performance it does for a given stage of flight, pitch plus power equals performance. I know that for certain attitudes and power settings and zero rate of climb will give me a certain airspeed. So if we have a instrument failure I know I only have to set up the variables I know and the others will sort themselves out.
HAve I got the right end of the stick with your question?