Time tracking: parent tasks and sub tasks

I use the time log to send reports to my clients. Some of my sub tasks titles are VERY unclear as they are sub tasks of other tasks or even sub tasks to sub tasks. 

It would be useful to have threaded columns in the exported CSV sheet. 

column 3, column 4, column 5, column 6

New web page for services / research, content, images, comments

i.e

Parent task: New web page for services / research

Sub tasks:

1. Layout and design

2. Content

a. Images (sub sub tasks)

b. Copy

3. Links from other pages

I thought the new category column would give me this opportunity to group tasks but understand its not the purpose of it. 

Another disturbing thing with the exported time log is the full url of all folders/projects which I always have to delete most of...