There seems to be a lot of discussion about this on GitHub, and I for one was just as confused in understanding what each of the filters does. From what I can tell the "pass" filter, as @njamster says, passes up to the parent. I would think having it labeled "pass to parent" would fit well. From one of the GitHub comments it seems that settings all parents and their children to Ignore on the nodes that are potentially blocking will at least get your mouse clicks registering, from there you can adjust. Not sure if this is the best advice, but it 's what worked for me and at least got me moving forward.