What about this example ?
Because Talend do not allow any cycle, so you can't link the three file to tUnite component directly.
To solve this issue, you can take the ways:
1) Copy and paste the input components with the same properties, so you can link the different outputs to tUnite component.(see screenshot 1)
2) Output the three outputs to three temporary files, then, read the data from these temporary and link to a tUnite component.(see screenshot 2)
Could you explain what you mean by 'cycle'.