HI @Abhrajit Ghosh? , thank you for reaching out!
There are metadata references in Trifacta that you can use. In order to get the filename as the column in your current data structure, use filepath as shown below
After adding the column, you can expand the row to get the filename and date. Use the extract transformation to extract the date value as a separate column. Bring the cursor to the row value, drag the cursor and select Apr2010. Use the suggestions - Extract value matching.
There are many suggestions. The selection of the Trifacta pattern will give a generic selection and will pick all the dates in the dataset
The preview will help to pick the correct pattern for all values in the sample. Hope this helps. Please let us know if you have any questions.
Best,
Apeksha Prasad