Local Database support for testing in shared environment

We have a shared DB and environment for testing and development - hence as such databases and its data are also shared (used by many teams).

Recently a couple of testing team has approached that they need favor to insert/ update / delete / create tables and its data for their component testing - now doing so in a shared environment will impact others who do not have the code to support that.

Please let me know how in a shared DB using alias / views etc can we simulate such a database setup