In most instances a student can be subject to a university's conduct code for misconduct that occurred off campus, or outside of the university bounds. Schools often have expansive jurisdiction written into their codes. There are some exceptions to this. I've dealt with cases where we've been able to find, for lack of a better way to put it, loopholes that would prevent a school from pursuing a case that it otherwise had intended to pursue.
That being said, the vast majority of instances, regardless of the alleged misconduct that took place off campus, whether it involves a Title IX sex offense or sexual misconduct, or a say potential general disciplinary issues such as a DUI, or a drug offense, or an alcohol violation, schools, if it can reflect upon or affect the university community, will often impose discipline or institute a disciplinary process against the accused student, even if the misconduct took place off campus. An experienced attorney advisor can help navigate the process, can help protect your rights.