Tape/Z is an evolving toolkit for analysing mainframe (z/OS) HLASM (High Level Assembler) code. The library provides capabilities for working with mainframe assembler code, including parsing, control flow graph building, dependency tracing, and flowchart visualisation capabilities.
Check it out at https://github.com/avishek-sen-gupta/tape-zSibling to Cobol-REKT (https://github.com/avishek-sen-gupta/cobol-rekt).