Q. How do I find a list of companies from a foreign country operating in Canada?

You can do this country by country (but not a comprehensive list globally). 

Go to Mergent Online.

In the Advanced search, enter the country of incorporation. Then under the far right tab ‘Textual Search’, select ‘Property’ and enter in Canada. This will pull up companies from whichever country you entered that have properties in Canada. 

See also LexisNexis Corporate Affliations (note: one user at a time). 

Hover of 'Subscriber Tools' and click on Advanced Search. 

Select ‘Parent Country’ as whichever country you're interested in, and then ‘Country’ as Canada.

That should pull up companies that are based in one country but which have a company in Canada.