How is an Open Door Policy supposed to be used?

You can utilize the open door policy at any time you want. You can tell your current leadership you are using it or you don't have to tell your leadership you are using it. It is regulations that ALL Commanders will have an open door policy. No one can stop you using the policy. So, you can take your issues up to your BN Command (or what ever level you have after your immediate unit) if you feel no resolution can be achieved with your immediate command. If nothing is resolved with BN level, then go up to Brigade. If that fails....you can take it up past your Brigade, file an IG complaint (if it fits within that realm) or file a congressional complaint.

Good responses below SPC (Join to see) , 1SG (Join to see) made a good point to be prepared when talking to the Commander. However, I would look to your NCO Support Channel first prior to going to the Commander. (1SG/CSM)
If your direct leadership (section leader) are unable or unwilling to help you resolve the issue, take it to the 1SG and then the CSM, especially for personnel issues. The CSM helps guide the 1SGs in the BN in personnel matters.
I always advise using language like: "I am asking for your guidance with a concern of mine that is hampering my ability to perform at my highest level", i.e. seek to be lead, not to hold others accountable for behavior you perceive as an injustice.
Without knowing the content of the conversation you had with your direct leaders and their response to it, I would not be comfortable telling you to utilize the open door policy. Too often, when a Soldier comes to me under the open door policy, I speak with the first-line leader and they are completely unaware of the problem and are more than willing to correct any issues. Usually, when I follow up with the Soldier, all is well.

4187, request a transfer. Then when they ask why, explain it.
Truthfully, I never cared for anonymous crap. If it's true, own it.

Regs have likely changed since my time but there is a reality piece. I always had my SEL screen ENL and XO screen OFF sides. They both knew no retaliation, no harm no foul, etc. They'd figure out the CoC dynamics so we'd get a picture of the issue and how it was being properly or improperly handled. I also required the SEL and XO to make an effort to solve at the lowest level. If I was going to still get it, then they'd fill me in. If the SM demanded they only see me, fine. But I never bit off on the meeting. You always hear a story; usually someone is picking on me or life is unfair. I take it in and let them know I'd get back in a few days. During that time, I'd activate the XO or SEL as appropriate to run the issue to ground, let me know the but fors, what fors, etc. and I'd have the SM back in. I look at the open door as being the last safety valve before JAG, IG, Hotline, or whatever. Advice to any Skipper; don't gaff it off. Even doing things right will still result in the few mortar rounds being launched upline. First reaction from upline is did the Skipper do their job right. Be prepared to show you did. Upline hates getting your messes on their desk, so make sure you resolve. My track record? About 1/3rd something worthwhile to deal with and 2/3rds life is not fair, make a stay in or get out decision. BTW, never hold a Come to Jesus Meeting against anybody. Just deal with the aftermath and encourage positive change and growth. Track record on the 2/3rds? About 50-50 but the decision they made was quick and the result was quick too.

There's lots of good advice in this string on the open door policy. CAPT Kevin B. provided good insight on how commanders use open door policies.

My concern is with the possible retaliation against you by your supervisors for an answer you put in what appears to be a Command Climate Survey. My experience with the Army shows commanders and CSMs take these surveys very seriously. They also take keeping the responses anonymous seriously. Some survey results and comments have a way of becoming top-down guidance to "fix the problem." If your supervisors somehow determined you made statements in the survey that required them to make changes, then it is likely they are violating Army policy or regulation by retaliating against you. This type of retaliation is often grounds for an IG complaint. You may report their behavior to the IG, but you must be sure it is in fact retaliatory behavior and that you can prove it. First, look at your own job performance and attitude before you file an IG complaint. If you supervisor's behavior is possibly the result of you being difficult to supervise or underperforming, then you're the one who may need to change. Your supervisors aren't required to like you or socialize with you. Their job is to accomplish the mission and train Soldiers. Also, an IG investigation will be painful for your supervisors and everybody in your chain. It may not improve your situation, but it may improve the unit and Army in the long run. For you, transfer is a good option.

Basically it is open door, come anytime policy from your company on up that a SM can utilize if they have a valid concern that they feel is not being handled in a timely or progressive manner. There is no appointment or permission necessary to utilize this despite what some may claim. However better results can and have been achieved by making an appointment.

Normally yes. In some instances, particularly when the leader is the problem you can get into see the next level. Make sure you are correct. You can check with JAG or the chaplain for guidance. Thank you for your service.

The commander's Open Door Policy should be written and posted with other mandatory policies. Since you're deployed, that may be unlikely.
Inform your first line supervisor that you request to see the commander under the Open Door Policy.
Before you do, consider writing down (1) what you believe the issue is, and (2) what outcome you seek.
With regard to the "anonymous" survey that you "outed" yourself on: consider what you wrote, and whether it was legitimate, whining, etc.
I'm not suggesting that it matters whether what you wrote on the survey was legitimate, or not, but you need to consider the perception of you that it generated.
Whether the survey was considered a "protected communication," depends on who administered it (e.g., IG, EEOA).
In general, communications with the IG, EEOA, or Member of Congress are considered "protected communications" and retaliation is prohibited.
So, unless it was a protected communication, it likely won't be considered retaliation. Retaliation for protected communications is prohibited.
Prohibited doesn't mean it won't happen, or that someone who retaliates will be punished. It only means it shouldn't happen.
If, in hindsight, you believe what you said was untrue, irresponsible, or a misunderstanding, own it.
If you alienated others it, doesn't mean it's retaliation. It could simply be you self-identified as someone who, based on what you wrote and how you wrote it, others now want to avoid you.
I'm not downing you. I'm trying to be realistic.
Whatever conclusion you reach, address it when you speak with the commander.
If you messed up, own it, and continue to march. You'll have to earn a different reputation.

I know it is late and not sure if you are still in. That said, you owned up to your mistake and are now paying for it. I'm not saying it is fair, but at least you owned up to it. I would ask that you go up the chain of command to resolve it. If it can't be done at the company level and you tried everything, go up to the battalion level. Nobody has the right to retaliate against you, if you find yourself in that situation, I would again work in out at the lowest level. If you have finally found yourself at the highest level and nothing happens after giving it time and following up, then I recommend IG.

An open door policy can be used in different ways, depending on the situation. If you have a manager who does not come across as transparent, and are worried about how he or she will respond to your concerns, for example, then an open door policy could be a useful tool. Open this https://www.sateer-hardware.com/ website to know more.