URL Rewrite using local traffic policy

It's a bit hard to determine which "somethings" you want to keep and which "somethings" you want to replace. Could you rephrase your example using unique qualifiers in each position? Or are the "somethings" always the same?

For example:

Outside: https://www.domain.com/something1/prod/something2/something3... Inside: https://www.domain.com/something1/something2/something3...

Depending on what you want to keep/replace and how difficult it is to parse, you may need to use an iRule instead of a Local Traffic Policy. LT policies are limited to a single Tcl line in the "replace with" string whereas with an iRule, you can manipulate the string in a much more granular fashion. That's not to say it can't be done with a policy but additional clarification is in order. Perhaps you can post what you have for your iRule already. That may provide enough information.