Finding paths NOT originating from you with lnd
I don't know if that possibility ever existed as an api call 8n lnd. but you can certainly call the describegraph api call to get all nodes and channels that are publically known. This json blob can easily be imported with a few lines of code as a graph in any graph library such as neo4j  or networkx once the network is there you can run any pathfinding algorithm from any source to any destination. Note that due to routing fees the shortest paths should be searched from destination to sender as the feerate is dynamic and depends on the fees that will have to be paid by future nodes and not only on the payment amount