Display nodes under Parent Taxonomy in Views
I have managed to work this one out.

Apparently you can add a filter using two methods:


"Simple hierarchical select" 
"Content: Has taxonomy terms (with depth; Simple hierarchical select)"


Select the second method Content: Has taxonomy terms (with depth; Simple hierarchical select) as the filter.

Then after selecting the filter, you then have the option to select which taxonomy term to use. After that just select Simple hierarchical select.

Next step was to just simply expose the filter to users, so they can manipulate it.