you can refer here, using SEDCMD , REGEX in props.conf and transforms.conf file in $SPLUNK_HOME/etc/system/local/ directory
http://docs.splunk.com/Documentation/Splunk/6.2.1/Data/Anonymizedatausingconfigurationfiles
Thanks for your response.But i need to know,how can I implement this in Data MOdel?
Like @Ayn wrote, use an eval expresion in your data model. Look at the docs for more details http://docs.splunk.com/Documentation/Splunk/6.2.1/Knowledge/Definedatamodelattributes
Use an eval expression. Something like this should do it.
replace(yourfield,"([^/]+)/([^/]+)/([^/]+)/([^/]+)","*/\2/*/\4")
To make this work via "add eval", you'd need to create a new field with a different name in the data model and hide the old field. The display name can be whatever you'd like.
Another option is to do that eval in a root search -> Add object -> Root search.
1234 should be replace by wild character