Dynamic Menu URL/Structure per User

I am building a multisite network which uses a single set of menus across all child sites, depending on whether or not a user is logged in. What I am attempting to do is add various menu buttons/options according to which type of user is logged in and who that particular user is.

I currently have one public menu and one user menu which is properly displaying over each child site. However, the user menu must be fluid/dynamic and create the hierarchy based upon that particular user. Additionally, I would like to relocate a few of the Buddypress links to my nav bar and remove the BP bar completely.

In other words, if user john-doe is logged in, there should be menu options such as:

http://mysite.com/john-doe/link-1”

http://mysite.com/john-doe/link-2”

And if user jane-smith is logged in, the same menu locations should instead point to:

http://mysite.com/jane-smith/link-1”

http://mysite.com/jane-smith/link-2”

I believe I will need a custom walker for this, but am not entirely sure how to proceed. Any ideas?