Great question. There have been a few similar questions over the years. You can find a fantastic answer about property here from /u/Cyberpunkapostle and another related specifically to reintegration here from /u/Talleyrayand and others.

I would just add for posterity that these answers may not relate specifically to Poland as post-war reparation policies varied by country. As mentioned in the first response, the experience of Jews in the Soviet Union was vastly different than those in Western Europe. The second answer(s) mention the experience of Jews from outside of Germany and provide some further sources.

I hope this helps some!