In an HTML Help modular Help system, you can create cross-module links, or links from one module topic to a topic in a different module. First, create a group in both the source and destination module projects, and index the destination topic to that group in the destination module project. Then, when the hub project is built and the link in the source module is clicked, it jumps to the topic in the destination module.
For example, suppose we have an HTML Help modular system with a hub project and two module projects that were created following the steps in the Creating a Modular Help Project for HTML Help topic. We can create a link from Module1 to Module2. We’ll call Module1 the source module, and Module2 will be the destination module since it contains the topic to which we want to link. Use the following steps:
1. Create a group named Modules in your Module1 project.
2. In your Module1 source document, create a group link to the Modules group.
4. Create a group named Modules in your Module2 project.
5. Assign the topic you want to link to from Module1 to the Modules group.
7. Open your hub project and create a Module1 and Module2 placeholder topic for the two modules. The placeholder topic text is generally formatted as Heading 1 topics, but you can use other heading levels as desired.
8. Click the Make Target button to build the hub HTML Help file.
9. In the hub project, choose the Help Target item from the left pane and the HTML Help target from the right pane of the project editor.
11. Click the project editor Topics icon.
12. Highlight one of the placeholder topics and enter the corresponding module Help file (.chm) name to the right of the MergeFile property.
13. Enter the corresponding module Help file (.hhc) name to the right of the MergeContents property. (The .hhc file name is normally the same as the .chm file name.)
14. Build the HTML Help target.
15. Copy the new module Help files (.chm) into the hub HTMLHelp output directory. Note that you do not have to copy the .hhc files into the hub Help file output directory.
16. Click the hub Help file View Target button.
17. Click the group link in your Module1 topic. It jumps to the topic assigned to the Modules group from your Module2 project.