multiple site plans at once?

JSL

I have a global-scale set of line segment buffers that I want to transform into dams. using the flattened site plan process (attached). However, when I select the buffers and zoom out far enough, the process ends up flattening the entire window and not the individual buffers, like in the lower part of this window for example:

Is it possible to modify the flattened site plan process to allow the creation of individual site plans for each area, like in the create concave hull process below:

JSL

Sorry, here's the line segments and buffers in a workspace.

td sgmts.zip