Graph view of a specific folder is possible by using “path:” search operator in graph filter
Reference: Search - Obsidian Help
From https://forum.obsidian.md/t/obsidian-release-v0-8-6/4770 :
Local graph now has an option to specify number of jumps from the current note.
So IMHO this request can be archived.
Navigation in/with graph view is explicitly requested in Graph Navigation Mode and Use local graph for navigation and might be already possible with Neo4j Graph View Plugin.