Provide an Option to select how the Search Function in lookups, contextual lookup entries, etc,. would work.
Currently by default it works as BEGIN WITH SEARCH.

Provide other options as a lookup in System Administration to select other values which can work as default everywhere instead of only Begin With Option.

Options like:
Contains, Ends with & Begins with.

You will have to customise only SysTableLookup & its base class for it to work.

Regards,