Build many dockerfiles on jenkins project

I have some task:

I have github repostiroy with folder "docker" and in this folder have many sub-folders with names (app1, app2, app3, etc.) with only Dockerfile in subfolder.

Sometimes i add new subfolder with name app50 and i want to Jenkins build automatically this new dockerfile and if all ok push new images to private docker registry.

How I can automate to select sub-folder, enter to him and run docker build ? with cutsom tag and name.

For example i upload new folder "app70-1.2.3" with Dockerfile. Jenkins need enter to folder "docker/app70-1.2.3" and run "docker build -t app70:1.2.3 ."