I live in an older apartment building with 4 units on the ground floor and 4 identical units on the on the second floor. Every time my upstairs neighbor washes dishes, and drains her sink, her dirty dishwater fills up my sink. This has been going on for a few months. It’s unsanitary and I want it to be fixed. I need to know what can be done to fix the problem and who is responsible for fixing it me, my neighbor, or the property manager?
If you need additional information, please let me know.
Thank you in advance for any, and all, responses.

The issue you are describing sounds like the kitchen stack is clogged below your sink since this stack serves more than just your unit the property manager is responsible for the scheduling and payment

Easy enough fix for any drain cleaning company

ditto

You definitely shouldn't have to deal with your neighbor's dishwater. Usually, that's a sign of a plumbing hiccup in the building. You shouldn’t have to fix it yourself. Give your property manager a shout about it. It's their job to sort out these kinds of issues, not yours. Just tell them what's happening and they should get a plumber to fix it. Hang in there, and don't be shy to nudge them until it's sorted!

You'll get a more Solution form there : [www.plbg.com]