Hi Bojja,
You can't set the label of a section with
`<fr:synchronize-repeated-content>`, but instead you can make the label of
the section depend on a value inside the section. In your example, you're
"setting" the value of `control-4` inside `section-2`. You can open the
"Section/Grid Settings" dialog for that section, to the "Label" tab, add a
Template Parameters you name `control-4`, set it to the value of
`control-4`, and in the title use `{$control-4}`.
You'll let me know if this works for you.