Config history for things like Feature Gates, Experiments, Dynamic Configs, and Segments can be accessed by clicking the "History" button on the top right of the page.
This page shows each change to a given config and the time that change was published.
For Feature Gates and Dynamic Configs, there is also a "Preview" and "Restore" option. These are meant to make it easy to revert to a previous state, particularly if you start rolling something out that is causing issues in production. The "preview" action will show a diff view between the current state of the gate and the previous state you selected, so you can make sure you are reverting to the correct state.