make (one's) position clear
To make one's opinion, point of view, or intention (about something) clearly understood. Often used with modifiers before the word "clear." You have to be sure to make your position very clear, both in person and in writing, so that if there's a dispute later on the other party can't claim to have been misinformed. The boss made his position on the issue crystal clear.
make someone's position clear
to clarify where someone stands on an issue. I don't think you understand what I said. Let me make my position dear. I can't tell whether you are in favor of or against the proposal. Please make your position clear.