If the file already exists in the project, you could make an update to the HTML, then use good old Windows Explorer to copy and paste the file into the other projects. As long as it exists already, there should be no need for importing.
An alternative would be to construct a topic in each project that presents the "Privilege" topic in an Inline Frame (IFRAME). Then you would simply maintain a single topic in a single location. The other topics would just point to it. The only problem with this approach is that the text of the Privilege topic wouldn't be searchable in the systems where you used the IFRAME.
Helpful and Handy Links
There are a couple of options available over and above the import option but without knowing more about your requirements it is difficult to say if they'd work for you.
The first is having all the content in a single project and using conditional build tags to exclude the content from each help file that you need. Depending on the number of different help files you have to produce and the overall number of topics, this may be a viable solution.
The second is to have the common topics in a separate project which is then merged into the others. This would require you to have the common topics in the same place in your TOC in all the projects though.
Other than these two solutions, there isn't much else to offer.
The RoboColum(n) @robocolumn Colum McAndrew