There are plenty of extensions that preventing the opening of new duplicated tabs. But I don't need them. When I open duplicate tab, I do it for a reason (90% of times).
I need an extension that actually find opened duplicate tabs in all Chrome windows and shows me a list of them so I can choose, which to close. Ok, I'm even agree extension will be closing them automatically after I press the button. And ok if it will not have list. But it must find duplicates in all windows and not prevent opening, but rather close on demand.
There is one extension I've found, but it (clams that it) searches tabs in one window, which is useless to me. https://chrome.google.com/webstore/detail/tab-dupectomy/nkkedbpcfdogedipgdhgeknjdphaplbk?hl=en