So the core of this claim is the Haavara (transfer) agreement, made between the Jewish Agency and the German government in 1933. The essence of it is that Jews would be allowed to emigrate and the Jewish agency would purchase German goods, while allowing German Jews to keep most of their property while migrating. This facilitated the migration of thousands of German Jews, but took the teeth out of the Jewish boycott of Germany during the 30s.

Anyway, the way Abbas and a lot of holocaust deniers see this as "look, the zionists and the nazis working together", but that's a backwards way of looking at it. The purpose of it was to get Jews out of Europe, and to Palestine. Working with the nazis was simply the necessary way of doing that. It's particularly telling that the nazis had no serious designs on a Jewish state (which you'd expect if they had an understanding with zionists), and planned on murdering the Jewish population of Palestine.

So yes, there is an underlying factual narrative, but the interpretation is…dubious, to put it kindly. Since the text has a clear political bent and contains holocaust denial, it's not a reliable historical resource on its own.