How to generate auto numbers sequentially specific to multi list

As part of Business requirement, we need to create one column in multi row attribute which needs to be automatically populated with the sequential numbers specific to the object in Oracle Cloud PLM. However, the auto sequence functionality, is only generating sequential numbers which are continuous and not specific to the object. For example, if we create an object1 on the Change request and if there are two rows added in multi row attribute group, the sequential number 1 and 2 is getting generated. However, if we create another new object2 on the change request/change order, the sequential number is