Welcome to the forum.
Unless you are using source control, RH cannot be used across
a network and sharing your drive is the same.
Either you need to split your project and then generate
merged help from the two project or you need to implement source
control.
The former will entail understanding how merged help works,
splitting the project and correcting the broken links that will
result. Not a task to be taken lightly. If your output is webhelp,
merged webhelp is described on my site.
Implementing source control is something I cannot help you
with.
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