Show only the first 2 bars on the Y-Axis using Chart.js?

I have a bar graph which needs to display a set of values like
Total Likes (likes on Facebook+Twitter+LinkenIn…)
Total Comments(comments on Facebook+Twitter+LinkenIn…)

My dataset currently holds Total Likes, Total Comments, Facebook Likes, Twitter likes etc)
I need the Facebook Likes, Twitter likes etc in my dataset since I need to show them in a tool tip.

So how do I limit my bar chart to only the first two bars in the group? Havent found an option when I was going through the chart.js APIs.