No, you can't eliminate it. The guests are not consumed (in the sense of destroyed), but merely incorporated into the complex. [G]0 is the total concentration of G in the solution, whether as free G molecules or in the complex.
What that means practically depends on how the experiment is performed, which you have left vague. You say it's a titration, so you are adding something to something, and concentrations will be changing.
For example, suppose you have an initial volume V0 of a solution of H of initial concentration [H]i, and titrate it with a solution of G of concentration [G]i. When you have added V1 of the G solution, the total volume V2 = V0 + V1 and
[H]0 = [H]i*V0/V2
[G]0 = [G]i*V1/V2