Wordpress Plugin Development

I'm building a company intranet system based on Wordpress with the Woffice theme and Buddypress plugin.

We have bought a frontend plugin (https://wperp.com/downloads/hr-frontend/) and we would like to integrate the "holiday calendar" from this plugin into the Buddypress user profiles. We would also like the calendar to be attributed to Buddypress groups showing all holiday's approved for team members within a Buddypress group. I also need that when a user requests a holiday that it sends a message to the Group Leader to approve or deny it.

The plugin already has a lot of these features, I just need them tweaking to work for us.