A recent reference question forced me to re-learn how to find a list of subsidiary companies and their addresses. In the past, Corporate Affiliations was my go-to for this question, but now that that database is defunct, I had to look for other options. Here are three to try out:
Business Insights: Global
Once you find the detail page on a company, look for the “View Company Hierarchy” icon:

Reference Solutions
Look for the “Corporate Tree” icon on a company detail page:

Uniworld Online
Thanks to Harold Gee for reminding me of this database! This one offers the most search options, info, and functionality (e.g., you can download results in an Excel file and have the foreign and domestic subsidiaries broken out separately).

UPDATE: See the comments to this blog post for more options, including “Corporate Affiliations” within the Nexis Uni database.