I have found the best way, for me, to accomplish this is to create the master file witht he sub projects lined. Go into the master and select the task and link just as you would in a “flat”/individual file.
Do keep in mind though, that strict discipline must be used when using any linking in MSOP as file corruptions can occur if you move or rename files. It is best if all the files reside on the same share within the same folder.
