If you've made changed in the command line you can reload the bigip.conf.bak file although this isn't ideal and only advised to get you out of a mess - Reloading this file will re-start TMM and would potentially drop connections.
If using an HA pair, you can sync the previous changes back to the active device - or promote the device with the old config on to active (assuming you don't have auto-sync enabled) This would be the safest method and would reduce impact to current sessions (depending how you have VIPs configured - mirroring etc)
Unfortunately there is no Nexus style equivalent feature for rolling back a change.. just planning :)