I have a custom dynamic block. Using c# I am able to iterate all instances of the dynamic block, get property and attributes values, etc. As part of the dynamic block there are labels and line objects. I need to get the bounds of the block. However, when I do so the extents of the block are including all the of other members, thereby making the block larger than what I am trying to achieve.

What I really need is to get the bound of a specific member of the dynamic block which is a polyline. I cannot figure out how to navigate the block programmatically to get to that object. Any help would be great appreciated. Thank you in advance. Here is my .dwg file: Link To DWG