At times, some of the ultra-nationalist and Nazi Ukrainian...

At times, some of the ultra-nationalist and Nazi Ukrainian Insurgent Army came into conflict with the ultra-Nationalist Nazi occupiers, but at the same time they were still involved in the mass murder of of jews, gypsies, poles, russians etc.
Most of the time they worked with and collaborated in the holocaust with the German Nazi's and sometimes some of the Ukrainian Insurgent Army were in disagreement over degrees of Ukrainian nationalism, but they weren't in any disagreement over Nazism or the holocaust.

Some further reading which I found interesting - https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3429340