Assuming you are using Data360 Analyze version 3.5.1 or higher you can use a Generate Data node to construct the required filename.

The output metadata is defined in the ConfigureFields property.
The built-in system 'RunDate_Pathsafe' run property provides the date in 'YYYYMMDD' format. See the Run property substitution topic in your Help documentation or online for the latest version of the product here ).
The other statements in the CreateRecords script define the components of the filename and then combine them so they can be output.

The generated filename is then input to the Excel File node which is configured to obtain the filename from the 'MonthlyFile' field:
