iRule for redirecting SharePoint traffic based on Path

That's L7 content switching. A redirect happens when you issue a HTTP 3xx response to another location.

when CLIENT_ACCEPTED {
  set poolDefault [LB::server pool]
}

when HTTP_REQUEST {
  switch -glob [string tolower [HTTP::path]] {
    "/path1*" { pool poolA }
    "/path2*" { pool poolB }
    "/pathN*" { pool poolN }
    default { pool $poolDefault }
  }
}