Glad I could be of help. Really appreciate what few of you are doing here with designs!

This looks really good! I like it very much.

I have a problem with filter placement, it breaks the connection between the parent/s and the children. But if you put it above the parents it may not be so obvious what you filter. Probably can be solved with different visual presentation. Or, if filter applies to the whole tree it can go above. I would also prefer that you don't have a second dimension(horizontal scroll of parents), just stack all levels vertically. Users will better understand the flow.

This is a very complex problem to solve, needs a lots of research. These were all my assumptions. I feel like most would like to see a top level picture, to see the start, how many levels are in between, and where where they are at in that flow right now. Maybe I am horribly wrong. Based on my design if you've noticed that users often wanna see 2 parents above we can add button to roll-out next parent above active problem. Even if data shows that most of the time users want to see 2 parents above, it can be a bit hectic to understand why and it creates a bit more complex pattern. I would prefer simple pattern with added cost of extra click to open up that next parent just to keep the pattern simple and make sure user understands where he's at. Again, this is only me and my assumptions.

Keep on rocking!