To the best of my knowledge, there were no Poles that took part in violence against the Jewish population of Lwow upon the arrival of German troops in the area in 1941. Reports from that time clearly identify the perpetrators as Ukrainians.
Overall, the general Polish population is not mentioned in German documents in respect of its participation as harassing Jews and helping the Germans. To the contrary; many German reports indicate that Poles felt anxiety for their own safety after the Jews disappeared. There are some German documents that mention some Poles, notably Polish police, railroad-workers and low-level employees in German offices but there was no Polish central authority collaborating with the Germans, as we find in e.g. Norway and its Quisling government or France and its Vichy regime. This was never the case in Poland.
As was the case in many European countries, there were also Polish individuals that played extortion games with Jews, but then there were also Poles that helped Jews under risk of facing death penalty from the German occupants. Both categories were relatively small in comparison to the general population, albeit one must take into consideration that most survivors made it through the war by Polish help and protection. A friend of mine, Bronia Klebanski, who is Jewish but lived on the “Aryan” side of society and was an active member of the Jewish underground in the Bialystok area, once told me a story of how she at a time took the train during the war, and was suddenly pointed out by a little girl who yelled “Jew!”. All the Polish passengers sat quietly, and nobody said anything to instigate further interest. This account is a small example of the general practice of non-collaboration among the Poles during the war.
In multi-ethnic Galicia and its capital Lwow, there were occasional acts of violence before the war as a result of ethnic tensions between the various groups.
This part of the inter-War Polish republic had belonged to the Austro-Hungarian monarchy prior World War I which, unlike the other partitioned parts of Poland that were under Russian and Prussian control, did not repress the Polish language which is why many Jews in the area spoke Polish and were quite familiar with Polish culture in their daily life. Therefore tensions between Poles and Jews were limited compared to other ethnic groups like the Ukrainians.
Notwithstanding, before the Second World war Jews experienced such tensions with Poles but not to the extent to alter peoples lifestyles; they weren’t driven out, their property not confiscated; people would still live their normal lives.
After the Soviet advance into Poland most incidents of reported violence in these areas of this time was between Ukrainians and Poles.
Regarding Babi Yar. This place was no concentration camp, but a location of a massacre. In September 1941 the Jews of Kiev were ordered to an assembly area, to be further led out to the ravine of Babi Yar. The idea of massacre was new to the Soviet Jews, and it is still debated whether Soviet authorities repressed information about Nazi crimes that had earlier occurred in Poland.
The execution place was guarded by German SS, police and Ukrainian collaborators. In Ukraine, contrary to Poland, where the Germans built secluded death camps, Jews were often massacred on the spot. The Nazi death camps in occupied Poland such as Treblinka, Belzec, Sobibor and Chelmno were all hidden to the public.
I have written extensively about these issues in my books.