We can provide the granular access to the partitions based on the role specified to the user groups. If a user has the privilege in a particular partition can modify or can not modify based on the privilege associated with the user role. Please refer the below links for more clarity.
Managing user accounts:
http://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/tmos_management_guide_10_1/tmos_users.html
Authentication:
http://support.f5.com/kb/en-us/solutions/public/14000/300/sol14324.html
Configuring Remote User Authentication and Authorization:
http://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/tmos-implementations-11-1-0/16.html