From what you have stated, I presume you are running through a folder with numerous (1 or more) files to be imported.

when you create a foreach loop to iterate through a folder, you will have created a variable to hold the file name (eg @User::FileName).

thus, for each iteration, the variable is populated with the relevant file name being retrieved.

this variable can then be used in any subsequent process (constraint in the process flow, in a conditional split, added to the list of columns using a derived column component and captured in a table, etc.

the question to be answered therefore: what is it you need to achieve with the file name?