Ah, you are referring to party roles, which are shown here, correct?
If so, then yes, the menu item has been disabled for the moment, the screen still exists. You can renable it, by removing the comments on line 66 & 76 in applications\party\widget\partymgr\PartyMenus.xml. Before you do, consider this however: There is a reason why we disabled it for now and that is, that partyroles are circumstantial at all times. Meaning that assinging a party role is useless without the context it serves in. The screenshot I attached is a decent example of that, there you can see that the Party “Company” has the following roles attached:
None of which are of any use by themselves: internal_organisation is used to mark company as part of the company operating the system but only comes into play inside of accounting, carrier means that the party acts as a carrier to deliver goods of sorts but requires the delivery methods and other info about the whereabouts of delivery in general, account is used inside of the CRM and still requires the information about specific parties that are assigned to this account, bill_to_customer and bill_from_vendor are both roles that play a role in accounting, where the party acts as one or the other during specific transactions. None of these can exist by themselves however and either adding or removing one will mess with the context it is being used in. We removed the link to the screen because of this and we strongly recommend to not add or modify roles on their own. If you require them, you will require them in the context of a specific use-case and then the use-case should take care of it.
OFBiz has a problem of overbloating the screens with information that can not be used by themselves. Sure, you can always display more, but often it will not add to the usability of the system. We do not follow the same road.
As for the tabs: When we worked on the party application, a tab navigation has not been available to our toolkit. We didn’t want to rely on multiple button rows, as those are deeply confusing, so we decided on moving the links that lead to sub-screens to the left sidebar:
With the newer applications, like accounting which we are currently working on, we are tranferring these tabs to a right-hand navigation, or to group-buttons. The other apps will be updated with these changes in future releases.