Maybe the transformer ShortestPathFinder?

here is an article explaining https://Shortest-Route-Calculations-with-the-ShortestPathFinder 

You’ll need to prepare the inputs:

and consider these usage notes 

• If ShortestPathFinder produces unexpected results, consider using AnchoredSnapper instead. Input the From-To Line through the Candidate input port and use the same value for Snapping Tolerance. Specify Snapping Type = End Point Snapping and Add Additional Vertex = NEVER.

• Only linear features with non-negative cost attribute values are allowed if the Cost Type is set to By One Attribute or By Two Attributes. If a feature does not have the attribute specified in the Forward Cost Attribute or the Reverse Cost Attribute, a zero cost is used for the line. Any features with a negative cost will be output through the <Rejected> port.