Hi,
if you chaining/editing the data source in ECC you need to replicate the data source form ECC to BI.
if you select the check box, checking the unhide fields you need to replicate.
go to BI system -> tx- RSDS -> give the data source name and source system -> go to data source menu -> replicate.
then check all the changes happen accordingly ECC system.
Thanks,
Phani.