You can use the free Joget Marketplace plugin File Link Datalist Formatter Plugin to display a download link for the file upload field in Datalist, but for one datalist (form) at a time. Read https://marketplace.joget.com/jw/web/userview/mp/mpp/_/vad?id=file_link_datalist_v1.

In this plugin, it works if I select an attachment field from one subform .

I need to display 5 fields from 5 different forms

This plugin I must choose 1 form for a datalist column 

Ex:

I have 2 forms

The first contains a file upload of id = attachment1 in table 'app_fd_comment'

the second form includes a form grid field that uses the above form and has an upload file field of id = attachemnt2 in the 'app_fd_post'

select attachment1 from app_fd_comment where id = '#requestParam.id#

union

select attachment2 from app_fd_post where c_fk = '#requestParam.id#

this query will result 3 records because I have 3 attachments,

I cannot make a column for each attachment because the number of the attachment are dynamic so one request may have 3 attachments and another may have 10 attachments