BI4 :unfold some part of table

Hi everyone

I have a trouble over a table that have breaks. and i want to fold all lines execpt one. this one is well known : it's a specific value from the break.

My report has prompt to define the values perimeter

When i do an unfold with a set of values , i should redo the unfold when i refresh over a new perimeter despite the value to unfold is there

thanks for your help