• Open the multi module spring boot project which has spring beans spans over different modules in the workspace.
• Search for a spring bean like a REST Controller symbol in the symbol explorer
• Open the symbole

The symbol is opened as a source file outside the project, its just uses the parent project and then open the file from the parent project. This disables all the Java navigation since the file is not opened as CU in Eclipse.

STS4 Versions:
Spring Tool Suite 4 Main Feature 4.14.1.202204131622 org.springframework.boot.ide.main.feature.feature.group VMware, Inc.

Eclipse Version:
Version: 2022-06 (4.24)
Build id: I20220419-1800