Creating links to PHP code and managing profile icons

I have read the documentation multiple times and I have googled my questions but either I am not asking the right questions or the answer is missing from the documentation.

We have a BuddyPress site for which i bought and installed Kleo. I know how to add menu items using ##profile_link## in the URL input from custom links. This presumably makes a pages that are only visible to the logged in user (correct?). So for example lets say I add this: ##profile_link##/nicefunction. I want it such that when someone clicks on the nicefunction menu item nicefunction.php is executed. Is there any documentation as how to do this?

My second question is, how do I manage (add, delete, etc.) icons in the icon bar below my avatar when I am logged in? For example how to add an icon where the red arrow is pointing that links through to nicefunction.php or how to delete one of the icons in the area I have marked around with a green line, and move it to the pull-down menu on the right? I have attached an image to clarify.

Thanks in advance for your help.

Happy to give you whatever access you may need but can’t see why you’d need it.