BuddyPress.org

Hi there! Im trying to make a timeline view for the activity stream. i will like to know which file I have to modify.
if i add <div class=”timelineBar”></div> in the browser under <div id=”content” class=”site-content col-md-9″ role=”main”>

and add to the css:
.timelineBar {
width: 2px;
background-color: #BDBDBD;
display: inline-block;
position: absolute;
height: 100%;
left: 50%;
margin-left: 10px;
margin-right: 10px;
I get this result

I will like to know where I have to add the <div class=”timelineBar”></div> and get the line to appear in the activity an attach the line to the post by the users.

this is the link of what Im trying to do.

Please HELP!!!

PS: Sorry For my English