How can I compare the changes in the current commit with the previous commit and retrieve the updated file in the specified path?

Question

on:
  push:
    branches:
      - main
    paths:
      - 'src/model/**/*.mdl'
      - 'Code/tests/03-Impl/01_Unittest/**/*.tpt'

jobs:
  build:
    runs-on: self-hosted
    steps:
      - uses: actions/checkout@v2

      - name: Run batch files for .tpt files
  shell: bash
  run: |
    shopt -s globstar
    base_path="code/tests/03-Impl/01_Unittest"
    # Fetch units based on directories under base_path
    units=("$base_path"/*)
    for unit_path in "${units[@]}"; do
    # Skip if not a directory
    if [ ! -d "$unit_path" ]; then
    continue
    fi
    # Check if the unit contains modified .tpt files
    modified_files=$(git diff --name-only HEAD~1 "$unit_path" | grep -E "\.tpt$")
    if [ -z "$modified_files" ]; then
    echo "Skipping unit: $unit_path"
    continue
    fi
    # Process batch files
    for batch_file in "$unit_path"/*.bat; do
    if [ -f "$batch_file" ]; then
      echo "Running batch file: $batch_file"
      cmd.exe /C start /b "$batch_file"
    fi
  done
  # Process modified .tpt files
  for file in $modified_files; do
    echo "Triggering batch file for unit: $unit_path"
    unit_name=$(basename "$unit_path")
    new_file_name="TR_CM_${unit_name}.bat"
    if [ -f "$unit_path/$new_file_name" ]; then
      echo "Running $new_file_name"
      cmd.exe /C start /b "$unit_path/$new_file_name"
    fi
  done
done

This is the script I am trying to implement. When a commit happens to the paths, the workflow will be triggered. The script should compare the commit changes with the last commit ID and fetch the files. If there are new changes in .mdl or .tpt files, the corresponding batch file in the .tpt directory should run. I have tried using this script. If you have any scripts or suggestions, please provide them. It would be greatly helpful to me. Thanks in advance!

If you have any scripts or suggestions, please provide them.