Wikipedia notes working turbo-compound engines were and are in production- admittedly, long after WW2 ended.
Yeah a handful of aircraft engines did use it, none was a great success and as I said, aircraft engines are much less demanding then tank engines in terms of operating conditions. They run for long periods in a narrow RPM band in clean air with only wind induced stresses on the driveshaft, rather then say, shock of a fifty ton tank slamming into a ditch or a stone wall and then immediately being thrown into reverse to get clear. They also blow up if you keep them stationary on the ground for too long, cooling limits are simply accepted with aeroengines, especially WW2 piston engines. Can't have that on a tank on a 115 degree F day.
I really can't think of what could be more abusive to an engine then powering a tank, except powering in a tank in ever worse terrain with worse quality of fuel/oil/filters. Anything you drive more violently is probably a damn lot lighter and not tracked, anything heavier is bound to be road/rails only or else very slow.
Do you mean they tried to use turbo-compounding in a tank engine? What examples are there?
Various experimental tank engines mainly in the 1950s. End result was everyone on earth uses either a diesel with or without some form of supercharging, or a pure gas turbine for the M1 Abrams and certain T-80 models only. Turbocompounding besides its inherent added complexity adds massive amounts of back pressure to the engine, increasing stress on every single component and thus reducing reliability of the entire system. Meanwhile a turbine will only ever work well in a narrow RPM range, while a diesel engine on a tank will be throttled up and down constantly. Joining the two together is not the greatest idea.
The idea is trying to make a comeback now for truck engines, but in very mild forms, like 5% power/economy kind of boost, alongside a whole slew of other expensive and difficult to maintain ideas to improve economy on internal combustion engines. Such small economy gains can be useful, but that's not really what was in mind for the Drakfic designs, nor for any of the actual uses for aircraft and tank power plants. Its also... use for long haul trucks, a very mild operating environment. Tank engine designers have opted to just increase compression ratios, and not even go very far on that, because reliability in action counts for more then saving a few gallons of fuel. Tanks waste huge amounts of fuel idling anyway, and turbocompounding will actually make your idle worse unless you have a wastegate to bypass the turbine at low power, but this requires yet more plumbing volume in the engine compartment. Of course for the modern comeback, well, lots of stuff will work acceptably today that wouldn't have a chance in hell in working fifty or sixty years ago. The Draka stories ignored this to a completely comical degree. The more rejected and unworkable a technological idea was, like say, compressed air power transmission, the more the Draka were given it and somehow became a global superpower in the process. With slaves no less. I don't even want to think about it anymore.
On a random note, one or two railway locomotives, and a Swedish cruiser used a hybrid of gas turbine and diesel engine which was sort of like turbo compounding, basically the diesel engine spun freely generating lots of exhaust gas, and this gas was piped into a completely separate power turbine. In this way each engine ran at its own speed, and the transmission could be simpler. The idea worked but it sure wasn't very efficient as an overall means of powering anything.