pattern oneHopOnPath(From, To) = {
  // describe possible connections that build up the path
}

// this should be replaced with the transitive closure call on oneHopOnPath
pattern pathExists(From, Next, To) = {
  find oneHopOnPath(From, Next);
  Next == To; // I'm not sure, maybe you need 'shareable' mode
} or {
  find onehopOnPath(From, Next);
  find pathExists(Next, To);
}

rule findPaths(From, To) = seq{
  
  iterate choose First with find pathExists(From, First, To) do seq{
    if(First == To) do seq{
      println("Single-hop path: " + name(From) + "->" + name(To));
    } else seq{
      println("Finding pathes " + name(From) + "->" + name(First) + "->" + name(To));
      call findPaths(First,To);
    }
  }
}

forall From,To with find oneStepOnPath(From,To) do
  call myNativeStoreHop(From,To);

call myNativeFindAllRoutes(Source,Target,Result);

forall Path with find pathInResult(Path,Result) do seq{
  // evaluate and use path
}