Hello Madhan,
You can apply the Regex filter to select list of files from the directory/directory tree and add to test suite.
For ex: If I want to filter filenames that starts with x and y, you can add File Regex Filter as x*.tst and y*.tst.
In below screenshot, we applied file filter to choose all filenames that has x and p.
If you still have any questions on applying File Regex Filter, please let me know.
Thanks
Srikanth Gajawada