Hi,
Go to OMSR and maintain the same field selection group (say, 200) for these similar fields like in ECC5. You can very well move the fields newly added to 200, to some other field selection group based on mandatory or optional.
In short, maintain the field selection group 200 as in ECC5 and proceed. In OMSR, you can maintain the field selection group as required. Change the field selection group of new fields to the field selection group of similar fields.
You can maintain the filed selection for field selection group in OMS9.
Test the same and revert back in case of any doubts.
Regards,
AKPT