Are there academic institution-specific equivalents to attorneys (a professional who assists in navigating conduct and justice systems)? There's an interesting question over at Law.SE on the possibility of suing a university over what the OP saw as unfair disciplinary practices. I have often wondered...
Is there a type of professional or professional practice related to advising or representing students and/or faculty within the context of internal disciplinary procedures?
As a concrete example, let us assume that Mary was expelled for allegedly falsifying data for her thesis. Mary contests this.

If she sues in civil court, she should consult an appropriately-qualified, local attorney.
But if she instead takes her argument directly to the university's disciplinary committee, she will need someone with an in-depth knowledge of the policies, procedures, rules of evidence, witness disqualification criteria, time limits, etc. that are internal to the university. This person could scrutinize the investigation in-depth and &quot;beat them at their own game&quot; by pointing out how the evidence, according to university policy, should be seen in her favor or does not meet the internal requirements for expulsion.

Another example might be a purely advisory context: perhaps one is considering a romantic liaison with a student, and is wondering whether this could affect their employment.
Does such a professional or service exist? Is this a domain of highly specialized &quot;regular&quot; lawyers? Is there a separate professional practice for academic advisors?
Clarifications:

This is a general question; I'm not currently facing a situation on which I need advice.
If necessary, we can limit the scope of the question to academic misconduct (plagiarism, falsifying data, cheating on exams, etc.) rather than personal misconduct.
I will tag this as US to further limit the scope, but I'm certainly interested in any answers, regardless of the location.
I’m not aware of what you are asking about existing as a type of professional that one can retain (as per your question) — I suspect that would be a rather poor way to make a living — but at my university there are people who are available to consult on matters such as Mary’s expulsion case.
Since Mary sounds like a graduate student, the relevant place to go would be the university ombuds office. In some cases the student union or an employee union of some sort may offer some help.
If Mary were a faculty member, she would go to a committee of our academic senate where advisers would be able to advise her if the thing she wants to complain about is a violation of her rights as a faculty member, and about the procedure for challenging the administration’s decisions.
These advisers are themselves regular faculty members like me and only do this as a “side gig” for a few hours a month, but they will have received specialized training that gives them the knowledge to offer this sort of advice (in fact I am currently on a sister subcommittee of this committee so I received a lot of the same training myself), and will also have auxiliary staff they can turn to who specialize in the relevant policy matters and can offer further information if the need arises.
These advisers won’t be available for an unlimited time. Likely they will be able to meet with Mary 2-3 times and discuss her questions, but it’s not quite the same as having your own lawyer or other professional that you retain on an hourly basis.
Since through my involvement in the sister subcommittee I am privy to faculty grievances a bit like Mary’s, I can tell you that faculty members who really need professional help with their grievance process will often hire a lawyer (I have also seen cases of students hiring lawyers for help with a disciplinary matter), and this can make a big difference - it’s far from easy for someone without experience in these administrative processes to navigate the system. A lawyer may not be intimately familiar with the specific institution’s policies, but broadly speaking they have the right training and skill set to help in such challenging situations. They don’t come cheap, however...