Hi @rohit782192
You should be able to just rename the .bak to .yxmd and then will be able to open in Alteryx as usual
The contents are identical. Just change the extension on the file name in your file browser, or Open the .bak file in Designer (File > Open Workflow > Browse, then set to "All Files (*.*)" and select the ,bak file. Then Save As the yxmd.
You can rename it - just remove .bak and then it'll be useable again from whence it was saved. Not everything will be present since the time of creation/saving may have some differences.