No one agrees with every decision. Disagreements are fine; it's what you do when you disagree that matters. (We all know people who love to have the "meeting after the meeting," where they've supported a decision in the meeting but then go out and undermine it.)

Show that you were professional. Show that you raised your concerns in a productive way. If you have an example that proves you can affect change, great... and if you don't, show that you can support a decision even though you think it was wrong (as long as it's not unethical, immoral, etc.)

Every company wants employees willing to be honest and forthright, to share concerns and issues... but to also get behind a decision and support it as if they agreed, even if they didn't.