Hi @Anonymous ,
According to your collection view, the "Department" column contains another table, not a text value. Assuming this formula is on a Text: property for a label, the error is just saying your formula resolves to a table, not a text value which it needs.
If you click into the Department table from the collection view, you should see the underlying table and columns which, presumably, contain the column you're actually looking for.
You would then need to adjust your formula to traverse that table as well, in order to return a value from a specific column - eg:
First(First(PradeepNewCol1).Department).Something
Assuming of course you're looking for the first row of the underlying table as well....
Hope this helps,
RT