I'm afraid that this isn't possible. (At least, not right now.)
A quick perusal of the Google Drive support forums shows other people also wanting to have more dynamic mailto: links in their Google Documents. (Surprisingly, this might be easier to do with Google Spreadsheets and the =hyperlink() function.)
Anyway, I did some experimentation.
A mailto: link with one Email address will work.
mailto:bigal@example.com
However, it has to be an email address. Using a name (so that Outlook will search for it in your address book) doesn't work.
I also tried a couple of other tricks to get multiple addresses in the link.
mailto:bigal@example.com?cc=littlejohn@example.com
That doesn't work. Nor did separating email addresses with commas instead of semi-colons, so that's not an issue.
So, it appears that in a Google Document you're limited to the very simplest mailto: link.
Assuming you're "locked in" to the Google eco-system, your options at this point are to either put email addresses into the document as plain text (so people can copy-paste directly to their email client compose window) or create an email alias for each group of people who should receive email messages from a document. (That last is certainly impractical for even small shops.)
Short Answer
At this time Google documents do not have a way to hide content.
Alternatives
An alternative is to publish to the web the document before you start to work in the sections that want to hide.
Another alternative is create a copy of the document and remove the content to share, then share the copy instead of the original.
References
Docs editors Help
Best Answer
It is not possible to share a document from within Google Documents and have it BCC all the recipients. This is a feature that has been requested a lot over the past several years on the Google product forums (e.g. here, here, here, and here), and so far Google has not implemented it.
I saw a couple people in those threads mention a workaround that will only work if you want to share a document to people with "can view" access. In that case, you share the document with "Can view" access to everyone but do not select the "Notify people via email" box. Then you take the link to the document and send it in a regular email to everyone in the Bcc line.
That workaround will not work if you want to share a document to people with "can edit" access. This is because anyone with edit access can click on the document's "Share" button and see all the other editors' email addresses.