Make it possible to publish only subfolders in a targeting site repository

Scenario: Having a single git repo which contains the site for a multi component project where each component site should be published at a different time point.

  /
 ..   index.html...
 +--- M1
 +--- M2
 +

I can configure to ignore paths like M1,M2 but I can't configure to use a target path while the content is being copied into the target site git repos to say that only the current content will be copied into M1 and this is the only part which is handle with updates/changes/deletes.
The root path can be handled by using the ignorePathsToDelete configuration but in the sub modules like M1 and M2 it is not possible to configure scm-publish in a way to handle only a sub folder.