All libraries provided by Infineon are specified in manifest files that are automatically found by the tools. Manifests are XML files that tell the Library Manager how to discover the list of available BSPs, libraries, and library dependencies. The manifest can also specify specific versions of libraries and dependent libraries that are meant to work together. For more information, refer to the Manifest chapter in the ModusToolbox™ tools package user guide.
You can create your own manifest file(s) for your libraries so that they will show up in the Library Manager and will work just like the Infineon libraries. More information on manifest files and how to create and use your own manifests is covered in the ModusToolbox™ tools package user guide.
In order to manage libraries that are specified in a manifest file in the application, files with the extension mtb are used. Their location and behavior depend on whether the library is a direct dependency or an indirect dependency. Normally the Library Manager is used to create/modify mtb files so you won't need to change them or even view them, but it is worthwhile to understand what is in them.