This depends on the mental condition of the person. Ask them to mediate which will give them power of self love.

Well, if you meant the office relationship issue between colleagues or between manager and subordinate then first thing one should do to help solving or help come around from it; is to approach to the person & tell sorry, if you are cause, if not then invite the person to talk/speak with you, might be at the time of having meals. This discussion is good at meals. It helps in getting focus on the topic and soon could be defocused by focusing on food when the discussion goes to bitter state. So bottom line is you need approach first & timed it well to help the person to get rid of trauma, by changing the attention/focus. You repeat the exact things that once you enjoyed well.

If you meant this happened otherwhere else in your personal life. Then the above things must be twisted and tried. By twisting means, help the person doing daily things, invite for a ride, dinner or movie. Then suggest the person, it is part of life and Life is bigger than all this, and work/walk together. Meditation could be also one of your suggestions as well.

Thanks
Sandeep